[10240010] |<article>English language</article>
[10240020] |'''English''' is an [[Indo-European languages|Indo-European]], [[West Germanic languages|West Germanic language]] originating in [[England]], and is the [[first language]] for most people in the [[United Kingdom]], the [[United States]], [[Canada]], [[Australia]], [[New Zealand]], [[Republic of Ireland|Ireland]], and the [[Anglophone Caribbean]].
[10240030] |It is used extensively as a [[second language]] and as an [[official language]] throughout the world, especially in [[Commonwealth of Nations|Commonwealth]] countries and in many [[international organization]]s.
[10240040] |==Significance== 
[10240050] |Modern English, sometimes described as the first global [[lingua franca]], is the [[Linguistic imperialism|dominant]] [[international auxiliary language|international language]] in [[communication]]s, [[science]], [[business]], [[aviation]], [[entertainment]], [[radio]] and [[diplomacy]].
[10240060] |The initial reason for its enormous spread beyond the bounds of the [[British Isles]] where it was originally a native tongue was the [[British Empire]], and by the late nineteenth century its influence had won a truly global reach.
[10240070] |It is the dominant language in the [[United States]] and the growing economic and cultural influence of that [[federal union]] as a global [[superpower]] since [[World War II]] has significantly accelerated adoption of English as a language across the planet.
[10240080] |A working knowledge of English has become a requirement in a number of fields, occupations and professions such as medicine and as a consequence over a billion people speak English to at least a basic level (see [[English language learning and teaching]]).
[10240090] |Linguists such as [[David Crystal]] recognize that one impact of this massive growth of English, in common with other global languages, has been to reduce native [[Natural language#Linguistic diversity|linguistic diversity]] in many parts of the world historically, most particularly in [[Australasia]] and [[North America]], and its huge influence continues to play an important role in [[language attrition]].
[10240100] |By a similar token, [[historical linguistics|historical linguists]], aware of the complex and fluid dynamics of [[language change]], are always alive to the potential English contains through the vast size and spread of the communities that use it and its natural internal variety, such as in its [[English-based creole languages|creoles]] and [[pidgin]]s, to produce a new [[language family|family]] of distinct languages over time.
[10240110] |English is one of six official languages of the [[United Nations]].
[10240120] |==History== 
[10240130] |English is a [[West Germanic languages|West Germanic]] language that originated from the [[Anglo-Frisian languages|Anglo-Frisian]] dialects brought to [[Great Britain|Britain]] by Germanic settlers and Roman auxiliary troops from various parts of what is now northwest Germany and the Northern [[Netherlands]].
[10240140] |Initially, [[Old English language|Old English]] was a diverse group of dialects, reflecting the varied origins of the Anglo-Saxon Kingdoms of [[England]].
[10240150] |One of these dialects, Late West Saxon, eventually came to dominate.
[10240160] |The original Old English language was then influenced by two waves of invasion.
[10240170] |The first was by language speakers of the [[North Germanic languages|Scandinavian]] branch of the Germanic family; they conquered and colonized parts of Britain in the 8th and 9th centuries.
[10240180] |The second was the [[Normans]] in the 11th century, who spoke Old Norman and ultimately developed an English variety of this called [[Anglo-Norman]].
[10240190] |These two invasions caused English to become "mixed" to some degree (though it was never a truly mixed language in the strict linguistic sense of the word; mixed languages arise from the cohabitation of speakers of different languages, who develop a hybrid tongue for basic communication).
[10240200] |Cohabitation with the Scandinavians resulted in a significant grammatical simplification and lexical supplementation of the Anglo-Frisian core of English; the later [[Normans|Norman]] occupation led to the grafting onto that Germanic core of a more elaborate layer of words from the [[Italic languages|Italic]] branch of the European languages.
[10240210] |This Norman influence entered English largely through the courts and government.
[10240220] |Thus, English developed into a "borrowing" language of great flexibility and with a huge vocabulary.
[10240230] |== Classification and related languages == 
[10240240] |The English language belongs to the western sub-branch of the [[Germanic languages|Germanic branch]] of the [[Indo-European languages|Indo-European]] family of languages.
[10240250] |The closest living relative of English is [[Scots language|Scots]], spoken primarily in Scotland and parts of Northern Ireland, which is viewed by linguists as either a separate language or a group of dialects of English.
[10240260] |The next closest relative to English after Scots is [[Frisian languages|Frisian]], spoken in the Northern Netherlands and Northwest Germany.
[10240270] |Other less closely related living [[West Germanic languages]] include [[Dutch language|Dutch]], [[Low German]], [[German language|German]] and [[Afrikaans]].
[10240280] |The [[North Germanic languages]] of Scandinavia are less closely related to English than the West Germanic languages.
[10240290] |Many [[French language|French]] words are also intelligible to an English speaker (though pronunciations are often quite different) because English absorbed a large vocabulary from [[Norman language|Norman]] and French, via [[Anglo-Norman]] after the Norman Conquest and directly from French in subsequent centuries.
[10240300] |As a result, a large portion of English vocabulary is derived from French, with some minor spelling differences (word endings, use of old French spellings, etc.), as well as occasional divergences in meaning, in so-called "faux amis", or [[false friend]]s.
[10240310] |The pronunciation of French loanwords in English has become completely anglicized and follows a typically Germanic pattern of stress.
[10240320] |== Geographical distribution == 
[10240330] |Approximately 375 million people speak English as their first language.
[10240340] |English today is probably the third largest language by number of native speakers, after [[Mandarin (linguistics)|Mandarin Chinese]] and [[Spanish language|Spanish]].
[10240350] |However, when combining native and non-native speakers it is probably the most commonly spoken language in the world, though possibly second to a combination of the [[Chinese language]]s, depending on whether or not distinctions in the latter are classified as "languages" or "dialects."
[10240360] |Estimates that include [[second language]] speakers vary greatly from 470 million to over a billion depending on how [[literacy]] or mastery is defined.
[10240370] |There are some who claim that non-native speakers now outnumber native speakers by a ratio of 3 to 1.
[10240380] |The countries with the highest populations of native English speakers are, in descending order: United States (215 million), United Kingdom (58 million), Canada (18.2 million), Australia (15.5 million), [[Republic of Ireland|Ireland]] (3.8 million), South Africa (3.7 million), and New Zealand (3.0-3.7 million).
[10240390] |Countries such as [[Jamaica]] and [[Nigeria]] also have millions of native speakers of [[dialect continuum|dialect continua]] ranging from an [[English-based creole languages|English-based creole]] to a more standard version of English.
[10240400] |Of those nations where English is spoken as a second language, India has the most such speakers ('[[Indian English]]') and linguistics professor [[David Crystal]] claims that, combining native and non-native speakers, India now has more people who speak or understand English than any other country in the world.
[10240410] |Following India is the [[People's Republic of China]].
[10240420] |===Countries in order of total speakers===
[10240430] |English is the primary language in [[Anguilla]], [[Antigua and Barbuda]], Australia ([[Australian English]]), the [[The Bahamas|Bahamas]], [[Barbados]], [[Bermuda]], [[Belize]] ([[Belizean Kriol language|Belizean Kriol]]), the [[British Indian Ocean Territory]], the [[British Virgin Islands]], Canada ([[Canadian English]]), the [[Cayman Islands]], the [[Falkland Islands]], [[Gibraltar]], [[Grenada]], [[Guam]], [[Guernsey]] ([[Channel Island English]]), [[Guyana]], Ireland ([[Hiberno-English]]), [[Isle of Man]] ([[Manx English]]), Jamaica ([[Jamaican English]]), [[Jersey]], [[Montserrat]], [[Nauru]], New Zealand ([[New Zealand English]]), [[Pitcairn Islands]], [[Saint Helena]], [[Saint Kitts and Nevis]], [[Saint Vincent and the Grenadines]], [[Singapore]], [[South Georgia and the South Sandwich Islands]], [[Trinidad and Tobago]], the [[Turks and Caicos Islands]], the United Kingdom, the [[United States Virgin Islands|U.S. Virgin Islands]], and the United States.
[10240440] |In many other countries, where English is not the most spoken language, it is an official language; these countries include [[Botswana]], [[Cameroon]], [[Dominica]], [[Fiji]], the [[Federated States of Micronesia]], [[Ghana]], [[The Gambia|Gambia]], [[India]], [[Kenya]], [[Kiribati]], [[Lesotho]], [[Liberia]], [[Madagascar]], [[Malta]], the [[Marshall Islands]], [[Mauritius]], [[Namibia]], [[Nigeria]], [[Pakistan]], [[Palau]], [[Papua New Guinea]], the [[Philippines]], [[Puerto Rico]], [[Rwanda]], the [[Solomon Islands]], [[Saint Lucia]], [[Samoa]], [[Seychelles]], [[Sierra Leone]], [[Sri Lanka]], [[Swaziland]], [[Tanzania]], [[Uganda]], [[Zambia]], and [[Zimbabwe]].
[10240450] |It is also one of the 11 official languages that are given equal status in South Africa ([[South African English]]).
[10240460] |English is also the official language in current [[dependent territory|dependent territories]] of Australia ([[Norfolk Island]], [[Christmas Island]] and [[Cocos Island]]) and of the United States ([[Northern Mariana Islands]], [[American Samoa]] and [[Puerto Rico]]), and in the former British colony of [[Hong Kong]].
[10240470] |English is an important language in several former [[colony|colonies]] and [[protectorate]]s of the United Kingdom but falls short of official status, such as in [[Malaysia]], [[Brunei]], [[United Arab Emirates]] and [[Bahrain]].
[10240480] |English is also not an official language in either the United States or the United Kingdom.
[10240490] |Although the United States federal government has no official languages, English has been given official status by 30 of the 50 state governments.
[10240500] |===English as a global language=== 
[10240510] |Because English is so widely spoken, it has often been referred to as a "[[world language]]", the ''[[lingua franca]]'' of the modern era.
[10240520] |While English is not an official language in most countries, it is currently the language most often taught as a [[second language]] around the world.
[10240530] |Some linguists believe that it is no longer the exclusive cultural sign of "native English speakers", but is rather a language that is absorbing aspects of cultures worldwide as it continues to grow.
[10240540] |It is, by international treaty, the official language for aerial and maritime communications.
[10240550] |English is an official language of the [[United Nations]] and many other international organizations, including the [[International Olympic Committee]].
[10240560] |English is the language most often studied as a foreign language in the European Union (by 89% of schoolchildren), followed by French (32%), German (18%), and Spanish (8%).
[10240570] |In the EU, a large fraction of the population reports being able to converse to some extent in English.
[10240580] |Among non-English speaking countries, a large percentage of the population claimed to be able to converse in English in the [[Netherlands]] (87%), [[Sweden]] (85%), [[Denmark]] (83%), [[Luxembourg]] (66%), [[Finland]] (60%), [[Slovenia]] (56%), [[Austria]] (53%), [[Belgium]] (52%), and [[Germany]] (51%).
[10240590] |[[Norway]] and [[Iceland]] also have a large majority of competent English-speakers.
[10240600] |[[Book]]s, [[magazine]]s, and [[newspaper]]s written in English are available in many countries around the world.
[10240610] |English is also the most commonly used language in the [[science]]s.
[10240620] |In 1997, the [[Science Citation Index]] reported that 95% of its articles were written in English, even though only half of them came from authors in English-speaking countries.
[10240630] |=== Dialects and regional varieties === 
[10240640] |The expansion of the British Empire and—since WWII—the primacy of the United States have spread English throughout the globe.
[10240650] |Because of that global spread, English has developed a host of [[List of dialects of the English language|English dialects]] and English-based [[creole language]]s and [[pidgin]]s.
[10240660] |The major [[Variety (linguistics)|varieties]] of English include, in most cases, several subvarieties, such as [[Cockney]] within [[British English]]; [[Newfoundland English]] within [[Canadian English]]; and [[African American Vernacular English]] ("Ebonics") and [[Southern American English]] within [[American English]].
[10240670] |English is a [[pluricentric language]], without a central language authority like France's [[Académie française]]; and, although no variety is clearly considered the only standard, there are a number of accents considered to be more prestigious, such as [[Received Pronunciation]] in Britain.
[10240680] |[[Scots language|Scots]] developed—largely independently—from the same origins, but following the [[Acts of Union 1707]] a process of [[language attrition]] began, whereby successive generations adopted more and more features from English causing dialectalisation.
[10240690] |Whether it is now a separate language or a [[dialect]] of English better described as [[Scottish English]] is in dispute.
[10240700] |The pronunciation, grammar and lexis of the traditional forms differ, sometimes substantially, from other varieties of English.
[10240710] |Because of the wide use of English as a second language, English speakers have many different [[Accent (linguistics)|accents]], which often signal the speaker's native dialect or language.
[10240720] |For the more distinctive characteristics of regional accents, see [[Regional accents of English]], and for the more distinctive characteristics of regional dialects, see [[List of dialects of the English language]].
[10240730] |Just as English itself has borrowed words from many different languages over its history, English [[loanword]]s now appear in a great many languages around the world, indicative of the technological and cultural influence of its speakers.
[10240740] |Several [[pidgin]]s and [[creole language]]s have formed using an English base, such as [[Jamaican (language)|Jamaican Patois]], [[Nigerian Pidgin]], and [[Tok Pisin]].
[10240750] |There are many words in English coined to describe forms of particular non-English languages that contain a very high proportion of English words.
[10240760] |[[Franglais]], for example, is used to describe French with a very high English word content; it is found on the [[Channel Islands]].
[10240770] |Another variant, spoken in the border bilingual regions of Québec in Canada, is called [[Franglais#Frenglish|Frenglish]].
[10240780] |In [[Wales]], which is part of the United Kingdom, the languages of [[Welsh language|Welsh]] and English are sometimes mixed together by fluent or comfortable Welsh speakers, the result of which is called [[Welsh English|Wenglish]].
[10240790] |=== Constructed varieties of English === 
[10240800] |* [[Basic English]] is simplified for easy international use.
[10240810] |It is used by manufacturers and other international businesses to write manuals and communicate.
[10240820] |Some English schools in Asia teach it as a practical subset of English for use by beginners.
[10240830] |* [[Special English]] is a simplified version of English used by the [[Voice of America]].
[10240840] |It uses a vocabulary of only 1500 words.
[10240850] |* [[English spelling reform|English reform]] is an attempt to improve collectively upon the English language.
[10240860] |* [[Seaspeak]] and the related [[NATO phonetic alphabet|Airspeak]] and Policespeak, all based on restricted vocabularies, were designed by [[Edward Johnson]] in the 1980s to aid international cooperation and communication in specific areas.
[10240870] |There is also a [[tunnelspeak]] for use in the [[Channel Tunnel]].
[10240880] |* [[Euro-English]] is a concept of standardising English for use as a second language in continental Europe.
[10240890] |* [[Manually Coded English]] — a variety of systems have been developed to represent the English language with hand signals, designed primarily for use in deaf education.
[10240900] |These should not be confused with true sign languages such as [[British Sign Language]] and [[American Sign Language]] used in Anglophone countries, which are independent and not based on English.
[10240910] |* [[E-Prime]] excludes forms of the verb ''to be''.
[10240920] |Euro-English (also ''EuroEnglish'' or ''Euro-English'') terms are English translations of European concepts that are not native to English-speaking countries.
[10240930] |Because of the United Kingdom's (and even the Republic of Ireland's) involvement in the European Union, the usage focuses on non-British concepts.
[10240940] |This kind of Euro-English was parodied when English was "made" one of the constituent languages of [[Europanto]].
[10240950] |== Phonology == 
[10240960] |=== Vowels ===
[10240970] |'''Notes:'''
[10240980] |It is the [[vowel]]s that differ most from region to region.
[10240990] |Where symbols appear in pairs, the first corresponds to American English, [[General American]] accent; the second corresponds to British English, [[Received Pronunciation]].
[10241000] |# American English lacks this sound; words with this sound are pronounced with {{IPA | /ɑ/}} or {{IPA | /ɔ/}}.
[10241010] |See [[Phonological history of English low back vowels#Lot-cloth split|''Lot-cloth split'']].
[10241020] |# Some dialects of North American English do not have this vowel.
[10241030] |See [[phonological history of English low_back vowels#Cot-caught merger|''Cot-caught merger'']].
[10241040] |# The North American variation of this sound is a [[r-colored vowel|rhotic vowel]].
[10241050] |# Many speakers of North American English do not distinguish between these two unstressed vowels.
[10241060] |For them, ''roses'' and ''Rosa's'' are pronounced the same, and the symbol usually used is [[schwa]] {{IPA | /ə/}}.
[10241070] |# This sound is often transcribed with {{IPA | /i/}} or with {{IPA | /ɪ/}}.
[10241080] |# The diphthongs {{IPA | /eɪ/}} and {{IPA | /oʊ/}} are monophthongal for many General American speakers, as {{IPA | /eː/}} and {{IPA | /oː/}}.
[10241090] |# The letter <''U''> can represent either {{IPA|/u/}} or the [[iotation|iotated]] vowel {{IPA|/ju/}}.
[10241100] |In BRP, if this iotated vowel {{IPA|/ju/}} occurs after {{IPA|/t/}}, {{IPA|/d/}}, {{IPA|/s/}} or {{IPA|/z/}}, it often triggers palatalization of the preceding consonant, turning it to {{IPA|/ʨ/}}, {{IPA|/ʥ/}}, {{IPA|/ɕ/}} and {{IPA|/ʑ/}} respectively, as in ''tune'', ''during'', ''sugar'', and ''azure''.
[10241110] |In American English, palatalization does not generally happen unless the {{IPA|/ju/}} is followed by ''r'', with the result that {{IPA|/(t, d,s, z)jur/}} turn to {{IPA|/tʃɚ/}}, {{IPA|/dʒɚ/}}, {{IPA|/ʃɚ/}} and {{IPA|/ʒɚ/}} respectively, as in ''nature'', ''verdure'', ''sure'', and ''treasure''.
[10241120] |# [[Vowel length]] plays a phonetic role in the majority of English dialects, and is said to be phonemic in a few dialects, such as [[Australian English]] and [[New Zealand English]].
[10241130] |In certain dialects of the modern English language, for instance [[General American]], there is allophonic vowel length: vowel phonemes are realized as long vowel allophones before voiced consonant phonemes in the coda of a syllable.
[10241140] |Before the [[Great Vowel Shift]], vowel length was phonemically contrastive.
[10241150] |# This sound only occurs in non-rhotic accents.
[10241160] |In some accents, this sound may be, instead of {{IPA|/ʊə/}}, {{IPA|/ɔ:/}}.
[10241170] |See [[English-language vowel changes before historic r]].
[10241180] |# This sound only occurs in non-rhotic accents.
[10241190] |In some accents, the schwa offglide of {{IPA|/ɛə/}} may be dropped, monophthising and lengthening the sound to {{IPA|/ɛ:/}}.
[10241200] |See also [[IPA chart for English dialects]] for more vowel charts.
[10241210] |=== Consonants === 
[10241220] |This is the English consonantal system using symbols from the [[International Phonetic Alphabet]] (IPA).
[10241230] |# The [[velar nasal]] {{IPA | [ŋ]}} is a non-phonemic allophone of /n/ in some northerly British accents, appearing only before /k/ and /g/.
[10241240] |In all other dialects it is a separate phoneme, although it only occurs in [[syllable coda]]s.
[10241250] |# The [[alveolar tap]] {{IPA | [ɾ]}} is an allophone of /t/ and /d/ in unstressed syllables in [[North American English]] and [[Australian English]].
[10241260] |This is the sound of ''tt'' or ''dd'' in the words ''latter'' and ''ladder'', which are homophones for many speakers of North American English.
[10241270] |In some accents such as [[Scottish English]] and [[Indian English]] it replaces {{IPA|/ɹ/}}.
[10241280] |This is the same sound represented by single ''r'' in most varieties of [[Spanish language|Spanish]].
[10241290] |# In some dialects, such as [[Cockney]], the interdentals /θ/ and /ð/ are usually merged with /f/ and /v/, and in others, like [[African American Vernacular English]], /ð/ is merged with dental /d/.
[10241300] |In some Irish varieties, /θ/ and /ð/ become the corresponding dental plosives, which then contrast with the usual alveolar plosives.
[10241310] |# The sounds {{IPA | /ʃ/, /ʒ/, and /ɹ/}} are labialised in some dialects.
[10241320] |Labialisation is never contrastive in initial position and therefore is sometimes not transcribed.
[10241330] |Most speakers of [[General American]] realize <r> (always rhoticized) as the [[retroflex approximant]] {{IPA|/ɻ/}}, whereas the same is realized in [[Scottish English]], etc. as the [[alveolar trill]].
[10241340] |# The [[voiceless palatal fricative]] /ç/ is in most accents just an [[allophone]] of /h/ before /j/; for instance ''human'' /çjuːmən/.
[10241350] |However, in some accents (see [[Phonological history of English consonant clusters|this]]), the /j/ is dropped, but the initial consonant is the same.
[10241360] |# The [[voiceless velar fricative]] /x/ is used by Scottish or Welsh speakers of English for Scots/Gaelic words such as ''loch'' {{IPA | /lɒx/}} or by some speakers for loanwords from German and Hebrew like ''Bach'' {{IPA|/bax/}} or ''Chanukah'' /xanuka/. /x/ is also used in South African English.
[10241370] |In some dialects such as [[Scouse]] ([[Liverpool]]) either {{IPA|[x]}} or the [[affricate consonant|affricate]] {{IPA|[kx]}} may be used as an [[allophone]] of /k/ in words such as ''docker'' {{IPA | [dɒkxə]}}.
[10241380] |Most native speakers have a great deal of trouble pronouncing it correctly when learning a foreign language.
[10241390] |Most speakers use the sounds [k] and [h] instead.
[10241400] |# Voiceless w {{IPA | [ʍ]}} is found in Scottish and Irish English, as well as in some varieties of American, New Zealand, and English English.
[10241410] |In most other dialects it is merged with /w/, in some dialects of Scots it is merged with /f/.
[10241420] |==== Voicing and aspiration ==== 
[10241430] |[[Voice (phonetics)|Voicing]] and [[aspiration (phonetics)|aspiration]] of [[stop consonant]]s in English depend on dialect and context, but a few general rules can be given: 
[10241440] |* Voiceless [[stop consonant|plosives]] and [[affricate consonant|affricates]] (/{{IPA | p}}/, /{{IPA | t}}/, /{{IPA | k}}/, and /{{IPA | tʃ}}/) are aspirated when they are word-initial or begin a stressed syllable — compare ''pin'' {{IPA | [pʰɪn]}} and ''spin'' {{IPA | [spɪn]}}, ''crap'' {{IPA | [kʰɹ̥æp]}} and ''scrap'' {{IPA | [skɹæp]}}.
[10241450] |** In some dialects, aspiration extends to unstressed syllables as well.
[10241460] |** In other dialects, such as [[Indian English]], all voiceless stops remain unaspirated.
[10241470] |* Word-initial voiced plosives may be devoiced in some dialects.
[10241480] |* Word-terminal voiceless plosives may be unreleased or accompanied by a glottal stop in some dialects (e.g. many varieties of [[American English]]) — examples: ''tap'' [{{IPA |tʰæp̚}}], ''sack'' [{{IPA |sæk̚}}].
[10241490] |* Word-terminal voiced plosives may be devoiced in some dialects (e.g. some varieties of [[American English]]) — examples: ''sad'' [{{IPA |sæd̥}}], ''bag'' [{{IPA |bæɡ̊}}].
[10241500] |In other dialects they are fully voiced in final position, but only partially voiced in initial position.
[10241510] |=== Supra-segmental features === 
[10241520] |==== Tone groups ==== 
[10241530] |English is an [[Intonation (linguistics)|intonation language]]. This means that the [[pitch (music)|pitch]] of the [[human voice|voice]] is used [[Syntax|syntactically]], for example, to convey [[surprise (emotion)|surprise]] and [[irony]], or to change a [[sentence (linguistics)|statement]] into a [[question]].
[10241540] |In English, intonation patterns are on groups of words, which are called tone groups, tone units, intonation groups or sense groups.
[10241550] |Tone groups are said on a single breath and, as a consequence, are of limited length, more often being on average five words long or lasting roughly two seconds.
[10241560] |For example:
[10241570] |: -{{IPA | /duː juː niːd ˈɛnɪˌθɪŋ/}} ''Do you need anything?''
[10241580] |: -{{IPA | <nowiki>/aɪ dəʊnt | nəʊ/</nowiki>}} ''I don't, no''
[10241590] |: -{{IPA | /aɪ dəʊnt nəʊ/}} ''I don't know'' (contracted to, for example, -{{IPA | /aɪ dəʊnəʊ/}} or {{IPA | /aɪ dənəʊ/}} ''I dunno'' in fast or colloquial speech that de-emphasises the pause between don't and know even further)
[10241600] |==== Characteristics of intonation ==== 
[10241610] |English is a strongly stressed language, in that certain syllables, both within words and within phrases, get a relative prominence/loudness during pronunciation while the others do not.
[10241620] |The former kind of syllables are said to be ''accentuated/stressed'' and the latter are ''unaccentuated/unstressed''.
[10241630] |All good dictionaries of English mark the accentuated syllable(s) by either placing an apostrophe-like ( {{IPA | ˈ}} ) sign either before (as in [[International Phonetic Alphabet|IPA]], [[Oxford English Dictionary]], or [[Merriam-Webster]] dictionaries) or after (as in many other dictionaries) the syllable where the stress accent falls.
[10241640] |Hence in a sentence, each tone group can be subdivided into syllables, which can either be stressed (strong) or unstressed (weak).
[10241650] |The stressed syllable is called the nuclear syllable.
[10241660] |For example:
[10241670] |: ''That | was | the | <u>'''best'''</u> | thing | you | could | have | '''done'''!''
[10241680] |Here, all syllables are unstressed, except the syllables/words ''best'' and ''done'', which are stressed.
[10241690] |''Best'' is stressed harder and, therefore, is the nuclear syllable.
[10241700] |The nuclear syllable carries the main point the speaker wishes to make.
[10241710] |For example:
[10241720] |: ''John'' had not stolen that money. (...
[10241730] |Someone else had.)
[10241740] |: John ''had not'' stolen that money. (...
[10241750] |Someone said he had. or ...
[10241760] |Not at that time, but later he did.)
[10241770] |: John had not ''stolen'' that money. (...
[10241780] |He acquired the money by some other means.)
[10241790] |: John had not stolen ''that'' money. (...
[10241800] |He had stolen some other money.)
[10241810] |: John had not stolen that ''money''. (...
[10241820] |He had stolen something else.)
[10241830] |Also
[10241840] |: ''I'' did not tell her that. (...
[10241850] |Someone else told her)
[10241860] |: I ''did not'' tell her that. (...
[10241870] |You said I did. or ... but now I will)
[10241880] |: I did not ''tell'' her that. (...
[10241890] |I did not say it; she could have inferred it, etc)
[10241900] |: I did not tell ''her'' that. (...
[10241910] |I told someone else)
[10241920] |: I did not tell her ''that''. (...
[10241930] |I told her something else)
[10241940] |This can also be used to express emotion:
[10241950] |: ''Oh'' really? (...I did not know that)
[10241960] |: Oh ''really''? (...I disbelieve you. or ...
[10241970] |That's blatantly obvious)
[10241980] |The nuclear syllable is spoken more loudly than the others and has a characteristic '''change of pitch'''.
[10241990] |The changes of pitch most commonly encountered in English are the '''rising pitch''' and the '''falling pitch''', although the '''fall-rising pitch''' and/or the '''rise-falling pitch''' are sometimes used.
[10242000] |In this opposition between falling and rising pitch, which plays a larger role in English than in most other languages, falling pitch conveys certainty and rising pitch uncertainty.
[10242010] |This can have a crucial impact on meaning, specifically in relation to polarity, the positive–negative opposition; thus, falling pitch means "polarity known", while rising pitch means "polarity unknown".
[10242020] |This underlies the rising pitch of yes/no questions.
[10242030] |For example:
[10242040] |: ''When do you want to be paid?''
[10242050] |: ''Now?''
[10242060] |(Rising pitch.
[10242070] |In this case, it denotes a question: "Can I be paid now?" or "Do you desire to pay now?")
[10242080] |: ''Now.''
[10242090] |(Falling pitch.
[10242100] |In this case, it denotes a statement: "I choose to be paid now.")
[10242110] |== Grammar == 
[10242120] |English grammar has minimal [[inflection]] compared with most other [[Indo-European languages]].
[10242130] |For example, Modern English, unlike Modern German or Dutch and the [[Romance languages]], lacks [[grammatical gender]] and [[Agreement (linguistics)|adjectival agreement]].
[10242140] |[[Grammatical case|Case]] marking has almost disappeared from the language and mainly survives in [[pronoun]]s.
[10242150] |The patterning of [[Strong inflection|strong]] (e.g. ''speak/spoke/spoken'') versus [[Germanic weak verb|weak verbs]] inherited from its Germanic origins has declined in importance in modern English, and the remnants of inflection (such as [[plural]] marking) have become more regular.
[10242160] |At the same time, the language has become more [[Isolating language|analytic]], and has developed features such as [[modal verb]]s and [[word order]] as resources for conveying meaning.
[10242170] |[[Auxiliary verb]]s mark constructions such as questions, negative polarity, the [[Grammatical voice|passive voice]] and progressive [[grammatical aspect|aspect]].
[10242180] |== Vocabulary == 
[10242190] |The English vocabulary has changed considerably over the centuries.
[10242200] |Like many languages deriving from [[Proto-Indo-European language|Proto-Indo-European]] (PIE), many of the most common words in English can trace back their origin (through the Germanic branch) to PIE.
[10242210] |Such words include the basic pronouns ''I'', from [[Old English language|Old English]] ''ic'', (cf. Latin ''ego'', Greek ''ego'', Sanskrit ''aham''), ''me'' (cf. Latin ''me'', Greek ''eme'', Sanskrit ''mam''), numbers (e.g. ''one'', ''two'', ''three'', cf. Latin ''unus, duo, tres'', Greek ''oinos'' "ace (on dice)", ''duo, treis''), common family relationships such as mother, father, brother, sister etc (cf. Greek "meter", Latin "mater", Sanskrit "matṛ"; ''mother''), names of many animals (cf. Sankrit ''mus'', Greek ''mys'', Latin ''mus''; ''mouse''), and many common verbs (cf. Greek ''gignōmi'', Latin ''gnoscere'', Hittite ''kanes'';'' to know'').
[10242220] |Germanic words (generally words of Old English or to a lesser extent Norse origin) tend to be shorter than the Latinate words of English, and more common in ordinary speech.
[10242230] |This includes nearly all the basic pronouns, prepositions, conjunctions, modal verbs etc. that form the basis of English syntax and grammar.
[10242240] |The longer Latinate words are often regarded as more elegant or educated.
[10242250] |However, the excessive use of Latinate words is considered at times to be either pretentious or an attempt to [[obfuscation|obfuscate]] an issue.
[10242260] |[[George Orwell]]'s [[essay]] "[[Politics and the English Language]]" is critical of this, as well as other perceived misuse of the language.
[10242270] |An English speaker is in many cases able to choose between Germanic and Latinate [[synonym]]s: ''come'' or ''arrive''; ''sight'' or ''vision''; ''freedom'' or ''liberty''.
[10242280] |In some cases there is a choice between a Germanic derived word (''oversee''), a Latin derived word (''supervise''), and a French word derived from the same Latin word (''survey'').
[10242290] |Such synonyms harbor a variety of different meanings and nuances, enabling the speaker to express fine variations or shades of thought.
[10242300] |Familiarity with the [[etymology]] of groups of synonyms can give English speakers greater control over their [[Register (sociolinguistics)|linguistic register]].
[10242310] |See: [[List of Germanic and Latinate equivalents in English]].
[10242320] |An exception to this and a peculiarity perhaps unique to English is that the nouns for meats are commonly different from, and unrelated to, those for the animals from which they are produced, the animal commonly having a Germanic name and the meat having a French-derived one.
[10242330] |Examples include: ''[[deer]]'' and ''[[venison]]''; ''[[cattle|cow]]'' and ''[[beef]]''; ''swine''/''[[pig]]'' and ''[[pork]]'', or ''[[domestic sheep|sheep]]'' and ''[[lamb and mutton|mutton]]''.
[10242340] |This is assumed to be a result of the aftermath of the Norman invasion, where a French-speaking elite were the consumers of the meat, produced by Anglo-Saxon lower classes.
[10242350] |Since the majority of words used in informal settings will normally be Germanic, such words are often the preferred choices when a speaker wishes to make a point in an argument in a very direct way.
[10242360] |A majority of Latinate words (or at least a majority of content words) will normally be used in more formal speech and writing, such as a [[court]]room or an [[encyclopedia]] article.
[10242370] |However, there are other Latinate words that are used normally in everyday speech and do not sound formal; these are mainly words for concepts that no longer have Germanic words, and are generally assimilated better and in many cases do not appear Latinate.
[10242380] |For instance, the words ''mountain'', ''valley'', ''river'', ''aunt'', ''uncle'', ''move'', ''use'', ''push'' and ''stay'' are all Latinate.
[10242390] |English easily accepts technical terms into common usage and often imports new words and phrases.
[10242400] |Examples of this phenomenon include: ''[[HTTP cookie|cookie]]'', ''[[Internet]]'' and ''[[Uniform Resource Locator|URL]]'' (technical terms), as well as ''[[genre]]'', ''[[über]]'', ''[[lingua franca]]'' and ''amigo'' (imported words/phrases from French, German, modern Latin, and Spanish, respectively).
[10242410] |In addition, [[slang]] often provides new meanings for old words and phrases.
[10242420] |In fact, this fluidity is so pronounced that a distinction often needs to be made between formal forms of English and contemporary usage.
[10242430] |See also: [[sociolinguistics]].
[10242440] |=== Number of words in English === 
[10242450] |The ''General Explanations'' at the beginning of the ''Oxford English Dictionary'' states:
[10242460] |The vocabulary of English is undoubtedly vast, but assigning a specific number to its size is more a matter of definition than of calculation.
[10242470] |Unlike other languages, such as [[Académie française|French]], [[List of language regulators|German]], [[Real Academia Española|Spanish]] and [[Accademia della Crusca|Italian]] there is no [[List of language regulators|Academy]] to define officially accepted words and spellings.
[10242480] |[[Neologism]]s are coined regularly in medicine, science and technology and other fields, and new [[slang]] is constantly developed.
[10242490] |Some of these new words enter wide usage; others remain restricted to small circles.
[10242500] |Foreign words used in immigrant communities often make their way into wider English usage.
[10242510] |Archaic, dialectal, and regional words might or might not be widely considered as "English".
[10242520] |The ''[[Oxford English Dictionary]],'' 2nd edition ''(OED2)'' includes over 600,000 definitions, following a rather inclusive policy:
[10242530] |The editors of ''[[Webster's Dictionary|Webster's Third New International Dictionary, Unabridged]]'' (475,000 main headwords) in their preface, estimate the number to be much higher.
[10242540] |It is estimated that about 25,000 words are added to the language each year.
[10242550] |=== Word origins === 
[10242560] |One of the consequences of the French influence is that the vocabulary of English is, to a certain extent, divided between those words which are [[Germanic languages|Germanic]] (mostly West Germanic, with a smaller influence from the North Germanic branch) and those which are "Latinate" (Latin-derived, either directly or from Norman French or other Romance languages).
[10242570] |Numerous sets of statistics have been proposed to demonstrate the origins of English vocabulary.
[10242580] |None, as yet, is considered definitive by most linguists.
[10242590] |A computerised survey of about 80,000 words in the old ''Shorter Oxford Dictionary'' (3rd ed.) was published in ''Ordered Profusion'' by Thomas Finkenstaedt and Dieter Wolff (1973) that estimated the origin of English words as follows:
[10242600] |*''[[Langues d'oïl|Langue d'oïl]]'', including French and [[Old Norman]]: [[List of English words of French origin|28.3%]]
[10242610] |*Latin, including modern scientific and technical Latin: 28.24%
[10242620] |*Other [[Germanic languages]] (including words directly inherited from [[Old English language|Old English]]): 25%
[10242630] |*Greek: 5.32%
[10242640] |*No etymology given: 4.03%
[10242650] |*Derived from proper names: 3.28%
[10242660] |*All other languages contributed less than 1% 
[10242670] |A survey by [[Joseph M. Williams]] in ''Origins of the English Language'' of 10,000 words taken from several thousand business letters gave this set of statistics: 
[10242680] |*French (langue d'oïl): 41%
[10242690] |*"Native" English: 33%
[10242700] |*Latin: 15%
[10242710] |*Danish: 2%
[10242720] |*Dutch: 1% 
[10242730] |*Other: 10%
[10242740] |However, 83% of the 1,000 most-common, and all of the 100 most-common English words are Germanic.
[10242750] |==== Dutch origins ==== 
[10242760] |Words describing the navy, types of ships, and other objects or activities on the water are often from Dutch origin.
[10242770] |''Yacht'' (''jacht'') and ''cruiser'' (''kruiser'') are examples.
[10242780] |==== French origins ==== 
[10242790] |There are many [[List of English words of French origin|words of French origin in English]], such as ''competition'', ''art'', ''table'', ''publicity'', ''police'', ''role'', ''routine'', ''machine'', ''force'', and many others that have been and are being [[anglicisation|anglicised]]; they are now pronounced according to English rules of [[phonology]], rather than French.
[10242800] |A large portion of English vocabulary is of French or [[Langues d'oïl]] origin, most derived from, or transmitted via, the [[Anglo-Norman language|Anglo-Norman]] spoken by the [[upper class]]es in [[England]] for several hundred years after the [[Norman conquest of England]].
[10242810] |== Writing system == 
[10242820] |English has been written using the [[Latin alphabet]] since around the ninth century.
[10242830] |(Before that, Old English had been written using [[Anglo-Saxon runes]].)
[10242840] |The spelling system, or [[orthography]], is multilayered, with elements of French, Latin and Greek spelling on top of the native Germanic system; it has grown to vary significantly from the [[phonology]] of the language.
[10242850] |The spelling of words often diverges considerably from how they are spoken.
[10242860] |Though letters and sounds may not correspond in isolation, spelling rules that take into account syllable structure, phonetics, and accents are 75% or more reliable.
[10242870] |Some phonics spelling advocates claim that English is more than 80% phonetic.
[10242880] |In general, [[history of the English language|the English language]], being the product of many other languages and having only been codified orthographically in the 16th century, has fewer consistent relationships between sounds and letters than many other languages.
[10242890] |The consequence of this orthographic history is that reading can be challenging.
[10242900] |It takes longer for students to become completely fluent readers of English than of many other languages, including French, Greek, and Spanish.
[10242910] |=== Basic sound-letter correspondence === 
[10242920] |Only the consonant letters are pronounced in a relatively regular way: 
[10242930] |=== Written accents === 
[10242940] |Unlike most other Germanic languages, English has almost no [[diacritic]]s except in foreign [[loanword]]s (like the [[acute accent]] in ''café''), and in the uncommon use of a [[diaeresis]] mark (often in formal writing) to indicate that two vowels are pronounced separately, rather than as one sound (e.g. ''naïve, Zoë'').
[10242950] |It is almost always acceptable to leave out the marks, especially in digital communications where the [[QWERTY]] keyboard lacks any marked letters, but it depends on the context where the word is used.
[10242960] |Some English words retain the diacritic to distinguish them from others, such as ''[[Animé (oleo-resin)|animé]], [[Investigative journalism|exposé]], [[Lamé (fencing)|lamé]], [[öre]], [[øre]], [[pâté]], [[piqué]],'' and ''[[rosé]]'', though these are sometimes also dropped (''[[résumé]]/resumé'' is usually spelled ''resume'' in the United States).
[10242970] |There are loan words which occasionally use a diacritic to represent their pronunciation that is not in the original word, such as ''maté'', from Spanish ''[[yerba mate]]'', following the French usage, but they are extremely rare.
[10242980] |== Formal written English == 
[10242990] |A version of the language almost universally agreed upon by educated English speakers around the world is called [[formal written English]].
[10243000] |It takes virtually the same form no matter where in the English-speaking world it is written.
[10243010] |In spoken English, by contrast, there are a vast number of differences between [[dialect]]s, [[Accent (linguistics)|accents]], and varieties of [[slang]], colloquial and regional expressions.
[10243020] |In spite of this, local variations in the formal written version of the language are quite limited, being restricted largely to the [[American and British English spelling differences|spelling differences between British and American English]].
[10243030] |== Basic and simplified versions == 
[10243040] |To make English easier to read, there are some simplified versions of the language.
[10243050] |One basic version is named ''[[Basic English]]'', a [[constructed language]] with a small number of words created by [[Charles Kay Ogden]] and described in his book ''Basic English: A General Introduction with Rules and Grammar'' (1930).
[10243060] |The language is based on a simplified version of English.
[10243070] |Ogden said that it would take seven years to learn English, seven months for [[Esperanto]], and seven weeks for Basic English, comparable with [[Ido]].
[10243080] |Thus Basic English is used by companies who need to make complex books for international use, and by language schools that need to give people some knowledge of English in a short time.
[10243090] |Ogden did not put any words into Basic English that could be said with a few other words and he worked to make the words work for speakers of any other language.
[10243100] |He put his set of words through a large number of tests and adjustments.
[10243110] |He also made the grammar simpler, but tried to keep the grammar normal for English users.
[10243120] |The concept gained its greatest publicity just after the [[World War II|Second World War]] as a tool for world peace.
[10243130] |Although it was not built into a program, similar simplifications were devised for various international uses.
[10243140] |Another version, [[Simplified English]], exists, which is a [[Controlled natural language|controlled language]] originally developed for [[aerospace]] industry maintenance manuals.
[10243150] |It offers a carefully limited and standardised subset of English.
[10243160] |Simplified English has a lexicon of approved words and those words can only be used in certain ways.
[10243170] |For example, the word ''close'' can be used in the phrase "Close the door" but not "do not go close to the landing gear".
[10250010] |<article>Esperanto</article>
[10250020] |is by far the most widely spoken [[constructed language|constructed]] [[international auxiliary language]] in the world.
[10250030] |Its name derives from ''Doktoro Esperanto,'' the [[pseudonym]] under which [[L. L. Zamenhof]] published the first book detailing Esperanto, the ''[[Unua Libro]],'' in 1887.
[10250040] |The word ''esperanto'' means 'one who hopes' in the language itself.
[10250050] |Zamenhof's goal was to create an easy and flexible language that would serve as a universal [[second language]] to foster peace and international understanding.
[10250060] |Esperanto has had continuous usage by a community estimated at between 100,000 and 2 million speakers for over a century.
[10250070] |By most estimates, there are approximately one thousand [[Native Esperanto speakers|native speakers]].
[10250080] |However, no country has adopted the language [[official language|officially]].
[10250090] |Today, Esperanto is employed in world travel, correspondence, cultural exchange, conventions, literature, language instruction, television, and radio broadcasting.
[10250100] |Also, there is an [[Esperanto Wikipedia]] that contains over 100,000 articles as of June 2008.
[10250110] |There is evidence that [[Propaedeutic value of Esperanto|learning Esperanto may provide a good foundation for learning languages in general]].
[10250120] |Some state education systems offer basic instruction and elective courses in Esperanto.
[10250130] |Esperanto is also the language of instruction in one university, the [[Akademio Internacia de la Sciencoj San Marino|Akademio Internacia de la Sciencoj]] in [[San Marino]].
[10250140] |== History == 
[10250150] |Esperanto was developed in the late 1870s and early 1880s by [[ophthalmology|ophthalmologist]] [[L. L. Zamenhof|Dr. Ludovic Lazarus Zamenhof]], an [[Ashkenazi Jew]] from [[Bialystok]], now in [[Poland]] and previously in the [[Polish-Lithuanian Commonwealth]], but at the time part of the [[Russian Empire]].
[10250160] |After some ten years of development, which Zamenhof spent translating literature into the language as well as writing original [[prose]] and [[Poetry|verse]], the [[Unua Libro|first book of Esperanto grammar]] was published in [[Warsaw]] in July 1887.
[10250170] |The number of speakers grew rapidly over the next few decades, at first primarily in the [[Russian empire]] and [[Eastern Europe]], then in [[Western Europe]], the [[Americas]], [[China]], and [[Japan]].
[10250180] |In the early years, speakers of Esperanto kept in contact primarily through correspondence and [[magazine|periodicals]], but in 1905 the first [[World Congress of Esperanto|world congress of Esperanto speakers]] was held in [[Boulogne-sur-Mer]], [[France]].
[10250190] |Since then world congresses have been held in different countries every year, except during the two [[world war|World Wars]].
[10250200] |Since the Second World War, they have been attended by an average of over 2000 and up to 6000 people.
[10250210] |===Relation to 20th-century totalitarianism=== 
[10250220] |As a potential vehicle for international understanding, Esperanto attracted the suspicion of many [[totalitarian]] states.
[10250230] |The situation was especially pronounced in [[Nazi Germany]] and in the [[Soviet Union]] under [[Joseph Stalin]].
[10250240] |In Germany, there was additional motivation to persecute Esperanto because Zamenhof was a Jew.
[10250250] |In his work ''[[Mein Kampf]],'' [[Hitler]] mentioned Esperanto as an example of a language that would be used by an [[International Jewry|International]] [[Jewish conspiracy|Jewish Conspiracy]] once they achieved [[world domination]].
[10250260] |[[Esperantist]]s were executed during [[the Holocaust]], with Zamenhof's family in particular singled out for execution.
[10250270] |In the early years of the Soviet Union, Esperanto was given a measure of government support, and an officially recognized Soviet Esperanto Association came into being.
[10250280] |However, in 1937, Stalin reversed this policy.
[10250290] |He denounced Esperanto as "the language of spies" and had Esperantists executed.
[10250300] |The use of Esperanto remained illegal until 1956.
[10250310] |==Official use== 
[10250320] |Esperanto has never been an official language of any recognized country.
[10250330] |However, there were plans at the beginning of the 20th century to establish [[Moresnet|Neutral Moresnet]] as the world's first Esperanto state.
[10250340] |In China, there was talk in some circles after the 1911 [[Xinhai Revolution]] about officially replacing [[Chinese language|Chinese]] with Esperanto as a means to dramatically bring the country into the twentieth century, though this policy proved untenable.
[10250350] |In the summer of 1924, the [[American Radio Relay League]] adopted Esperanto as its official [[international auxiliary language]], and hoped that the language would be used by [[Amateur radio|radio amateurs]] in international communications, but its actual use for radio communications was negligible.
[10250360] |In addition, the self-proclaimed [[artificial island]] [[micronation]] of [[Republic of Rose Island|Rose Island]] used Esperanto as its official language in 1968.
[10250370] |Esperanto is the working language of several [[non-profit organization|non-profit]] international organizations such as the ''[[Sennacieca Asocio Tutmonda]]'', but most others are specifically Esperanto organizations.
[10250380] |The largest of these, the [[World Esperanto Association]], has an official consultative relationship with the [[United Nations]] and [[UNESCO]].
[10250390] |The U.S. Army has published military phrasebooks in Esperanto, to be used in [[Military simulation|wargames]] by mock enemy forces.
[10250400] |Esperanto is also the first language of teaching and administration of the [[Akademio Internacia de la Sciencoj San Marino|International Academy of Sciences San Marino]], which is sometimes called an "Esperanto University".
[10250410] |== Linguistic properties == 
[10250420] |=== Classification === 
[10250430] |As a [[constructed language]], Esperanto is not [[Genealogy|genealogically]] related to any [[ethnic group|ethnic]] language.
[10250440] |It has been described as "a language [[lexicon|lexically]] predominantly [[Romance languages|Romanic]], [[morphology (linguistics)|morphologically]] intensively [[agglutination|agglutinative]] and to a certain degree [[isolating languages|isolating]] in character".
[10250450] |The [[phonology]], [[grammar]], [[vocabulary]], and [[semantics]] are based on the western [[Indo-European languages]].
[10250460] |The [[phoneme|phonemic inventory]] is essentially [[Slavic languages|Slavic]], as is much of the semantics, while the [[vocabulary]] derives primarily from the [[Romance languages]], with a lesser contribution from the [[Germanic languages]].
[10250470] |[[Pragmatics]] and other aspects of the language not specified by Zamenhof's original documents were influenced by the native languages of early speakers, primarily [[Russian language|Russian]], [[Polish language|Polish]], [[German language|German]], and [[French language|French]].
[10250480] |[[Linguistic typology|Typologically]], Esperanto has [[preposition]]s and a [[information flow|pragmatic word order]] that by default is ''[[Subject Verb Object]]'' and ''[[Word order|Adjective Noun]]''.
[10250490] |New words are formed through extensive [[prefix (linguistics)|prefix]]ing and [[suffix]]ing.
[10250500] |=== Writing system === 
[10250510] |Esperanto is written with a modified version of the [[Latin alphabet]], including six [[Letter (alphabet)|letters]] with [[diacritic]]s: [[c-circumflex|ĉ]], [[g-circumflex|ĝ]], [[h-circumflex|ĥ]], [[j-circumflex|ĵ]], [[s-circumflex|ŝ]] and [[u-breve|ŭ]] (that is, ''c, g, h, j, s'' [[circumflex]], and ''u'' [[breve]]).
[10250520] |The alphabet does not include the letters ''q, w, x,'' or ''y'' except in unassimilated foreign names.
[10250530] |The 28-letter alphabet is: <big><center>'''a b c ĉ d e f g ĝ h ĥ i j ĵ k l m n o p r s ŝ t u ŭ v z'''</center></big>
[10250540] |All letters are pronounced approximately as in the [[IPA]], with the exception of ''c'' and the accented letters: 
[10250550] |Two [[ASCII]]-compatible writing conventions are in use.
[10250560] |These substitute [[Digraph (orthography)|digraph]]s for the accented letters.
[10250570] |The original "h-convention" (''ch, gh, hh, jh, sh, u'') is based on English 'ch' and 'sh', while a more recent "[[x-convention]]" (''cx, gx, hx, jx, sx, ux'') is useful for alphabetic word sorting on a [[computer]] (''cx'' comes correctly after ''cu'', ''sx'' after ''sv'', etc.) as well as for simple conversion back into the standard [[orthography]].
[10250580] |Another scheme represents the superscripted letters by a [[caret]] (^), as for example: c^ or ^c.
[10250590] |=== Phonology === 
[10250600] |:''(For help with the phonetic symbols, see [[Help:IPA]])''
[10250610] |Esperanto has 22 [[consonant]]s, 5 [[vowel]]s, and two [[semivowel]]s, which combine with the vowels to form 6 [[diphthong]]s.
[10250620] |(The consonant {{IPA|/j/}} and semivowel {{IPA|/i̯/}} are both written <j>.)
[10250625] |[[tone (linguistics)|Tone]] is not used to distinguish meanings of words.
[10250630] |[[Stress (linguistics)|Stress]] is always on the penultimate vowel, unless a final vowel ''o'' is [[Elision|elided]], a practice which occurs mostly in [[poetry]].
[10250640] |For example, ''familio'' "family" is stressed {{IPA2|fa.mi.ˈli.o}}, but when found without the final o, ''famili’,'' the stress does not shift: {{IPA|[fa.mi.ˈli]}}.
[10250650] |==== Consonants ==== 
[10250660] |The 22 consonants are:
[10250670] |The sound {{IPA|/r/}} is usually [[alveolar trill|rolled]], but may be [[alveolar flap|tapped]] {{IPA|[ɾ]}}.
[10250680] |The {{IPA|/v/}} has a normative pronunciation like an [[English language|English]] ''v,'' but is sometimes somewhere between a ''v'' and a ''w,'' {{IPA|[ʋ]}}, depending on the language background of the speaker.
[10250690] |A semivowel {{IPA|/u̯/}} normally occurs only in [[diphthong]]s after the vowels {{IPA|/a/}} and {{IPA|/e/}}, not as a consonant {{IPA|*/w/}}.
[10250700] |Common, if debated, [[assimilation (linguistics)|assimilation]] includes the pronunciation of {{IPA|/nk/}} as {{IPA|[ŋk]}}, as in English ''sink,'' and {{IPA|/kz/}} as {{IPA|[gz]}}, like the ''x'' in English ''example''.
[10250710] |A large number of consonant clusters can occur, up to three in initial position and four in medial position, as in ''instrui'' "to teach".
[10250720] |Final clusters are uncommon except in foreign names, poetic elision of final ''o,'' and a very few basic words such as ''cent'' "hundred" and ''post'' "after".
[10250730] |====Vowels==== 
[10250740] |Esperanto has the five [[cardinal vowels]] of [[Spanish language|Spanish]], [[Swahili language|Swahili]], and [[Modern Greek]].
[10250750] |There are six falling diphthongs: ''uj, oj, ej, aj, aŭ, eŭ'' ({{IPA|/ui̯, oi̯, ei̯, ai̯, au̯, eu̯/}}).
[10250760] |With only five vowels, a good deal of variation is tolerated.
[10250770] |For instance, {{IPA|/e/}} commonly ranges from {{IPA|[e]}} (French ''é'') to {{IPA|[ɛ]}} (French ''è'').
[10250780] |The details often depend on the speaker's native language.
[10250790] |A [[glottal stop]] may occur between adjacent vowels in some people's speech, especially when the two vowels are the same, as in ''heroo'' "hero" ({{IPA|[he.ˈro.o]}} or {{IPA|[he.ˈro.ʔo]}}) and ''praavo'' "great-grandfather" ({{IPA|[pra.ˈa.vo]}} or {{IPA|[pra.ˈʔa.vo]}}).
[10250800] |=== Grammar === 
[10250810] |Esperanto words are [[Derivation (linguistics)|derived]] by stringing together [[prefix (linguistics)|prefix]]es, [[Root (linguistics)|roots]], and [[suffix]]es.
[10250820] |This process is regular, so that people can create new words as they speak and be understood.
[10250830] |[[Compound (linguistics)|Compound]] words are formed with a modifier-first, [[head (linguistics)|head-final]] order, the same order as English "birdsong" ''vs.'' "songbird".
[10250840] |The different [[Part of speech|parts of speech]] are marked by their own suffixes: all [[common noun]]s end in ''-o,'' all [[adjective]]s in ''-a,'' all derived adverbs in ''-e,'' and all [[verb]]s in one of six [[Grammatical tense|tense]] and [[Grammatical mood|mood]] suffixes, such as [[present tense]] ''-as.''
[10250850] |[[Grammatical number|Plural]] nouns end in ''-oj'' (pronounced "oy"), whereas [[direct object]]s end in ''-on.''
[10250860] |Plural direct objects end with the combination ''-ojn'' (pronounced to rhyme with "coin"): That is, ''-o'' for a noun, plus ''-j'' for plural, plus ''-n'' for direct object.
[10250870] |Adjectives [[Grammatical number#Effect of number on verbs and other parts of speech|agree]] with their nouns; their endings are plural ''-aj'' (pronounced "eye"), direct-object ''-an,'' and plural direct-object ''-ajn'' (pronounced to rhyme with "fine").
[10250880] |The suffix ''-n'' is used to indicate the goal of movement and a few other things, in addition to the direct object.
[10250890] |See [[Esperanto grammar]] for details.
[10250900] |The six verb [[inflection]]s consist of three tenses and three moods.
[10250910] |They are [[present tense]] ''-as,'' [[future tense]] ''-os,'' [[past tense]] ''-is,'' [[infinitive|infinitive mood]] ''-i,'' [[conditional mood]] ''-us,'' and [[jussive mood]] ''-u'' (used for wishes and commands).
[10250920] |Verbs are not marked for person or number.
[10250930] |For instance: ''kanti'' "to sing"; ''mi kantas'' "I sing"; ''mi kantis'' "I sang"; ''mi kantos'' "I will sing"; ''li kantas'' "he sings"; ''vi kantas'' "you sing".
[10250940] |Word order is comparatively free: Adjectives may precede or follow nouns, and subjects, verbs and objects (marked by the suffix ''-n)'' may occur in any order.
[10250950] |However, the [[article (grammar)|article]] ''la'' "the" and [[demonstrative]]s such as ''tiu'' "this, that" almost always come before the noun, and a [[preposition]] such as ''ĉe'' "at" ''must'' come before it.
[10250960] |Similarly, the negative ''ne'' "not" and [[conjunction]]s such as ''kaj'' "both, and" and ''ke'' "that" must precede the [[phrase]] or [[clause]] they introduce.
[10250970] |In [[copula]]r (A = B) clauses, word order is just as important as it is in English clauses like "people are dogs" ''vs.'' "dogs are people".
[10250980] |====Correlatives==== 
[10250990] |A [[correlative]] is a word used to ask or answer a question of who, where, what, when, or how.
[10251000] |Correlatives in Esperanto are set out in a systematic manner that correlates a basic [[idea]] (quantity, manner, time, ''etc.'') to a function (questioning, indicating, negating, ''etc.'') 
[10251010] |Examples: 
[10251020] |*''Kio estas tio?''
[10251030] |"What is this?"
[10251040] |*''Kioma estas la horo?''
[10251050] |"What time is it?"
[10251060] |Note ''kioma'' rather than ''Kiu estas la horo?'' "which is the hour?", when asking for the ranking order of the hour on the clock.
[10251070] |*''Io falis el la ŝranko'' "Something fell out of the cupboard."
[10251080] |*''Homoj tiaj kiel mi ne konadas timon.''
[10251090] |"Men such as me know no fear."
[10251100] |Correlatives are declined if the case demands it: 
[10251110] |*''Vi devas elekti ian vorton pli simpla'' "You should choose a (some kind of) simpler word."
[10251120] |''Ia'' receives ''-n'' because it's part of the [[direct object]].
[10251130] |*''Kian libron vi volas?''
[10251140] |"What sort of book do you want?"
[10251150] |Contrast this with, ''Kiun libron vi volas?''
[10251160] |"Which book do you want?"
[10251170] |=== Vocabulary === 
[10251180] |The core vocabulary of Esperanto was defined by ''Lingvo internacia'', published by Zamenhof in 1887.
[10251190] |It comprised 900 roots, which could be expanded into tens of thousands of words with prefixes, suffixes, and compounding.
[10251200] |In 1894, Zamenhof published the first Esperanto [[dictionary]], ''Universala Vortaro'', with a larger set of roots.
[10251210] |However, the rules of the language allowed speakers to borrow new roots as needed, recommending only that they look for the most international forms, and then derive related meanings from these.
[10251220] |Since then, many words have been borrowed, primarily but not solely from the Western European languages.
[10251230] |Not all proposed borrowings catch on, but many do, especially [[technical terminology|technical]] and [[science|scientific]] terms.
[10251240] |Terms for everyday use, on the other hand, are more likely to be derived from existing roots—for example ''komputilo'' (a computer) from ''komputi'' (to compute) plus the suffix ''-ilo'' (tool)—or to be covered by extending the meanings of existing words (for example ''muso'' (a mouse), as in English, now also means a computer input device).
[10251250] |There are frequent debates among Esperanto speakers about whether a particular borrowing is justified or whether the need can be met by deriving from or extending the meaning of existing words.
[10251260] |In addition to the root words and the rules for combining them, a learner of Esperanto must memorize some idiomatic compounds that are not entirely straightforward.
[10251270] |For example, ''eldoni'', literally "to give out", is used for "to publish" (a [[calque]] of words in several European languages with the same derivation), and ''vortaro'', literally "a collection of words", means "a glossary" or "a dictionary".
[10251280] |Such forms are modeled after usage in some European languages, and speakers of other languages may find them illogical.
[10251290] |Fossilized derivations inherited from Esperanto's source languages may be similarly obscure, such as the opaque connection the root word ''centralo'' "power station" has with ''centro'' "center".
[10251300] |Compounds with ''-um-'' are overtly arbitrary, and must be learned individually, as ''-um-'' has no defined meaning.
[10251310] |It turns ''dekstren'' "to the right" into ''dekstrumen'' "clockwise", and ''komuna'' "common/shared" into ''komunumo'' "community", for example.
[10251320] |Nevertheless, there are not nearly as many idiomatic or [[slang]] words in Esperanto as in ethnic languages, as these tend to make international communication difficult, working against Esperanto's main goal.
[10251330] |===Useful phrases=== 
[10251340] |Here are some useful Esperanto phrases, with [[help:IPA|IPA]] transcriptions:
[10251350] |* Hello: ''Saluton'' {{IPA|/sa.ˈlu.ton/}}
[10251360] |* What is your name?: ''Kiel vi nomiĝas?''
[10251370] |{{IPA|/ˈki.el vi no.ˈmi.ʤas/}}
[10251380] |* My name is...: ''Mi nomiĝas...''
[10251390] |{{IPA|/mi no.ˈmi.ʤas/}}
[10251400] |* How much (is it/are they)?: ''Kiom (estas)?''
[10251410] |{{IPA|/ˈki.om ˈes.tas/}}
[10251420] |* Here you are: ''Jen'' {{IPA|/jen/}}
[10251430] |* Do you speak Esperanto?: ''Ĉu vi parolas Esperanton?''
[10251440] |{{IPA|/ˈʧu vi pa.ˈro.las es.pe.ˈran.ton/}}
[10251450] |* I do not understand you: ''Mi ne komprenas vin'' {{IPA|/mi ˈne kom.ˈpre.nas vin/}}
[10251460] |* I like ''this'' one: ''Ĉi tiu plaĉas al mi'' {{IPA|/ʧi ˈti.u ˈpla.ʧas al ˈmi/}} or ''Mi ŝatas tiun ĉi'' {{IPA|/mi ˈʃa.tas ˈti.un ˈʧi/}} 
[10251470] |* Thank you: ''Dankon'' {{IPA|/ˈdan.kon/}}
[10251480] |* You're welcome: ''Ne dankinde'' {{IPA|/ˈne dan.ˈkin.de/}}
[10251490] |* Please: ''Bonvolu'' {{IPA|/bon.ˈvo.lu/}} or ''mi petas'' {{IPA|/mi ˈpe.tas/}}
[10251500] |* Here's to your health: ''Je via sano'' {{IPA|/je ˈvi.a ˈsa.no/}}
[10251510] |* Bless you!/Gesundheit!: ''Sanon!''
[10251520] |{{IPA|/ˈsa.non/}}
[10251530] |* Congratulations!: ''Gratulon!''
[10251540] |{{IPA|/ɡra.ˈtu.lon/}}
[10251550] |* Okay: ''Bone'' {{IPA|/ˈbo.ne/}} or ''Ĝuste'' {{IPA|/ˈʤus.te/}}
[10251560] |* Yes: ''Jes'' {{IPA|/ˈjes/}}
[10251570] |* No: ''Ne'' {{IPA|/ˈne/}}
[10251580] |* It is a nice day: ''Estas bela tago'' {{IPA|/ˈes.tas ˈbe.la ˈta.ɡo/}}
[10251590] |* I love you: ''Mi amas vin'' {{IPA|/mi ˈa.mas vin/}}
[10251600] |* Goodbye: ''Ĝis (la) (revido)'' {{IPA|/ʤis la re.ˈvi.do/}}
[10251610] |* One beer, please: ''Unu bieron, mi petas.''
[10251620] |{{IPA|/ˈu.nu bi.ˈe.ron, mi ˈpe.tas/}}
[10251630] |* What is that?: ''Kio estas tio?''
[10251640] |{{IPA|/ˈki.o ˈes.tas ˈti.o/}}
[10251650] |* That is...: ''Tio estas...''
[10251660] |{{IPA|/ˈti.o ˈes.tas/}}
[10251670] |* How are you?: ''Kiel vi (fartas)?''
[10251680] |{{IPA|/ˈki.el vi ˈfar.tas/}}
[10251690] |* Good morning!: ''Bonan matenon!''
[10251700] |{{IPA|/ˈbo.nan ma.ˈte.non/}}
[10251710] |* Good evening!: ''Bonan vesperon!''
[10251720] |{{IPA|/ˈbo.nan ves.ˈpe.ron/}}
[10251730] |* Good night!: ''Bonan nokton!''
[10251740] |{{IPA|/ˈbo.nan ˈnok.ton/}}
[10251750] |* Peace!: ''Pacon!''
[10251760] |{{IPA|/ˈpa.tson/}}
[10251770] |=== Sample text === 
[10251780] |The following short extract gives an idea of the character of Esperanto.
[10251790] |(Pronunciation is covered above.
[10251800] |The main point for English speakers to remember is that the letter 'J' has the sound of the letter 'Y' in English)
[10251810] |* Esperanto text
[10251820] |:''En multaj lokoj de Ĉinio estis temploj de drako-reĝo. Dum trosekeco oni preĝis en la temploj, ke la drako-reĝo donu pluvon al la homa mondo.
[10251830] |Tiam drako estis simbolo de la supernatura estaĵo. Kaj pli poste, ĝi fariĝis prapatro de la plej altaj regantoj kaj simbolis la absolutan aŭtoritaton de feŭda imperiestro.
[10251840] |La imperiestro pretendis, ke li estas filo de la drako. Ĉiuj liaj vivbezonaĵoj portis la nomon drako kaj estis ornamitaj per diversaj drakofiguroj.
[10251850] |Nun ĉie en Ĉinio videblas drako-ornamentaĵoj kaj cirkulas legendoj pri drakoj.''
[10251860] |*English Translation:
[10251870] |:In many places in China there were temples of the dragon king.
[10251880] |During times of drought, people prayed in the temples, that the dragon king would give rain to the human world.
[10251890] |At that time the dragon was a symbol of the supernatural.
[10251900] |Later on, it became the ancestor of the highest rulers and symbolised the absolute authority of the feudal emperor.
[10251910] |The emperor claimed to be the son of the dragon.
[10251920] |All of his personal possessions carried the name ''dragon'' and were decorated with various dragon figures.
[10251930] |Now everywhere in China dragon decorations can be seen and there circulate legends about dragons.
[10251940] |== Education == 
[10251950] |The majority of Esperanto speakers learn the language through self-directed study, online tutorials, and correspondence courses taught by volunteers.
[10251960] |In more recent years, teaching websites like ''[[lernu!]]'' have become popular.
[10251970] |Esperanto instruction is occasionally available at schools, such as a [[Esperanto#Esperanto and language acquisition|pilot project involving four primary schools]] under the supervision of the [[University of Manchester]], and by one count at 69 universities.
[10251980] |However, outside of [[China]] and [[Hungary]], these mostly involve informal arrangements rather than dedicated departments or state sponsorship.
[10251990] |[[Eötvös Loránd University]] in Budapest had a department of Interlinguistics and Esperanto from 1966 to 2004, after which time instruction moved to vocational colleges; there are state examinations for Esperanto instructors.
[10252000] |Various educators have estimated that Esperanto can be learned in anywhere from one quarter to one twentieth the amount of time required for other languages.
[10252010] |Some argue, however, that this is only true for native speakers of Western European languages.
[10252020] |[[Claude Piron]], a psychologist formerly at the [[University of Geneva]] and Chinese-English-Russian-Spanish translator for the United Nations, argued that Esperanto is far more "brain friendly" than many ethnic languages.
[10252030] |"Esperanto relies entirely on innate reflexes [and] differs from all other languages in that you can always trust your natural tendency to generalize patterns. [...]
[10252040] |The same [[neuropsychology|neuropsychological]] law [— called by] [[Jean Piaget]] ''generalizing assimilation'' — applies to word formation as well as to grammar."
[10252050] |=== Language acquisition === 
[10252060] |Four primary schools in Britain, with some 230 pupils, are currently following a course in "propedeutic Esperanto", under the supervision of the University of Manchester.
[10252070] |That is, instruction in Esperanto to raise language awareness and accelerate subsequent learning of foreign languages.
[10252080] |Several studies demonstrate that studying Esperanto before another foreign language speeds and improves learning the second language to a greater extent than other languages which have been investigated.
[10252090] |This appears to be because learning subsequent foreign languages is easier than learning one's first, while the use of a grammatically simple and culturally flexible auxiliary language like Esperanto lessens the first-language learning hurdle.
[10252100] |In one study, a group of European [[secondary school]] students studied Esperanto for one year, then French for three years, and ended up with a significantly better command of French than a control group, who studied French for all four years.
[10252110] |Similar results were found when the course of study was reduced to two years, of which six months was spent learning Esperanto.
[10252120] |Results are not yet available from a study in Australia to see if similar benefits would occur for learning East Asian languages, but the pupils taking Esperanto did better and enjoyed the subject more than those taking other languages.
[10252130] |== Community == 
[10252140] |=== Geography and demography === 
[10252150] |Esperanto speakers are more numerous in Europe and East [[Asia]] than in the Americas, [[Africa]], and [[Oceania]], and more numerous in [[urban area|urban]] than in [[rural]] areas.
[10252160] |Esperanto is particularly prevalent in the northern and eastern countries of Europe; in China, [[Korea]], Japan, and [[Iran]] within Asia; in [[Brazil]], [[Argentina]], and [[Mexico]] in the Americas; and in [[Togo]] in Africa.
[10252170] |====Number of speakers==== 
[10252180] |An estimate of the number of Esperanto speakers was made by the late [[Sidney S. Culbert]], a [[retirement|retired]] [[psychology]] [[professor]] at the [[University of Washington]] and a longtime Esperantist, who tracked down and tested Esperanto speakers in sample areas in dozens of countries over a period of twenty years.
[10252190] |Culbert concluded that between one and two million people speak Esperanto at [[ILR or Foreign Service Level language ability measures|Foreign Service Level 3]], "professionally proficient" (able to communicate moderately complex ideas without hesitation, and to follow speeches, radio broadcasts, etc.).
[10252200] |Culbert's estimate was not made for Esperanto alone, but formed part of his listing of estimates for all languages of over 1 million speakers, published annually in the [[World Almanac|World Almanac and Book of Facts]].
[10252210] |Culbert's most detailed account of his methodology is found in a 1989 letter to David Wolff .
[10252220] |Since Culbert never published detailed intermediate results for particular countries and regions, it is difficult to independently gauge the accuracy of his results.
[10252230] |In the Almanac, his estimates for numbers of language speakers were rounded to the nearest million, thus the number for Esperanto speakers is shown as 2 million.
[10252240] |This latter figure appears in ''[[Ethnologue]]''.
[10252250] |Assuming that this figure is accurate, that means that about 0.03% of the world's population speaks the language.
[10252260] |This falls short of Zamenhof's goal of a [[international auxiliary language|universal language]], but it represents a level of popularity unmatched by any other constructed language.
[10252270] |Marcus Sikosek (now [[Ziko van Dijk]]) has challenged this figure of 1.6 million as exaggerated.
[10252280] |He estimated that even if Esperanto speakers were evenly distributed, assuming one million Esperanto speakers worldwide would lead one to expect about 180 in the city of [[Cologne, Germany|Cologne]].
[10252290] |Van Dijk finds only 30 [[fluency|fluent]] speakers in that city, and similarly smaller than expected figures in several other places thought to have a larger-than-average concentration of Esperanto speakers.
[10252300] |He also notes that there are a total of about 20,000 members of the various Esperanto organizations (other estimates are higher).
[10252310] |Though there are undoubtedly many Esperanto speakers who are not members of any Esperanto organization, he thinks it unlikely that there are fifty times more speakers than organization members.
[10252320] |[[Finnish people|Finnish]] [[linguistics|linguist]] Jouko Lindstedt, an expert on native-born Esperanto speakers, presented the following scheme to show the overall proportions of language capabilities within the Esperanto community:
[10252330] |* ''1,000 have Esperanto as their native language
[10252340] |* ''10,000 speak it fluently
[10252350] |* ''100,000 can use it actively
[10252360] |* ''1,000,000 understand a large amount passively
[10252370] |* ''10,000,000 have studied it to some extent at some time.''
[10252380] |In the absence of Dr. Culbert's detailed sampling data, or any other census data, it is impossible to state the number of speakers with certainty.
[10252390] |Few observers, probably, would challenge the following statement from the [[website]] of the [[World Esperanto Association]]: 
[10252400] |:Numbers of [[textbook]]s sold and membership of local societies put the number of people with some knowledge of the language in the hundreds of thousands and possibly millions.
[10252410] |====Native speakers==== 
[10252420] |Ethnologue reports estimates that there are 200 to 2000 native Esperanto speakers ''(denaskuloj),'' who have learned the language from birth from their Esperanto-speaking parents.
[10252430] |This usually happens when Esperanto is the chief or only common language in an international family, but sometimes in a family of devoted Esperantists.
[10252440] |The most famous native speaker of Esperanto is businessman [[George Soros]].
[10252450] |Also notable is young Holocaust victim [[Petr Ginz]], whose drawing of the planet Earth as viewed from the moon was carried aboard the Space Shuttle ''[[Space Shuttle Columbia|Columbia]]'' in 2003 ([[STS-107]]).
[10252460] |=== Culture === 
[10252470] |Esperanto speakers can access an international [[culture]], including a large body of original as well as translated [[Esperanto literature|literature]].
[10252480] |There are over 25,000 Esperanto books, both originals and translations, as well as several regularly distributed [[List of Esperanto magazines|Esperanto magazines]].
[10252490] |Esperanto speakers use the language for free accommodations with [[Esperantist]]s in 92 countries using the [[Pasporta Servo]] or to develop [[pen pal]] friendships abroad through the Esperanto Pen Pal Service.
[10252500] |Every year, 1,500-3,000 Esperanto speakers meet for the [[World Congress of Esperanto]] ''(Universala Kongreso de Esperanto)''.
[10252510] |The [[European Esperanto Union]] ''(Eǔropa Esperanto-Unio)'' regroups the national Esperanto associations of the EU member states and holds congresses every two years.
[10252520] |The most recent was in [[Maribor, Slovenia]], in July-August 2007.
[10252530] |It attracted 256 delegates from 28 countries, including 2 members of the [[European Parliament]], Ms. [[Małgorzata Handzlik]] of [[Poland]] and Ms. [[Ljudmila Novak]] of [[Slovenia]].
[10252540] |Historically, much [[Esperanto music]] has been in various folk traditions, such as ''Kaj Tiel Plu'', for example.
[10252550] |In recent decades, more rock and other modern genres have appeared, an example being the Swedish band ''Persone''.
[10252560] |There are also shared [[tradition]]s, such as [[Zamenhof Day]], and shared [[behaviour]] patterns.
[10252570] |[[Esperantist]]s speak primarily in Esperanto at [[World Esperanto Congress|international Esperanto meetings]].
[10252580] |Detractors of Esperanto occasionally criticize it as "having no culture".
[10252590] |Proponents, such as Prof. [[Humphrey Tonkin]] of the [[University of Hartford]], observe that Esperanto is "culturally neutral by design, as it was intended to be a facilitator between cultures, not to be the carrier of any one national culture."
[10252610] |The late [[Scotland|Scottish]] Esperanto author [[William Auld]] has written extensively on the subject, arguing that Esperanto is "the expression of a [[Esperanto as an international language|common human culture]], unencumbered by national frontiers.
[10252620] |Thus it is considered a culture on its own."
[10252630] |Others point to Esperanto's potential for strengthening a common European identity, as it combines features of several [[Esperanto etymology|European languages]].
[10252640] |====In popular culture==== 
[10252650] |Esperanto has been used in a number of films and novels.
[10252660] |Typically, this is done either to add the exotic flavour of a foreign language without representing any particular ethnicity, or to avoid going to the trouble of inventing a new language.
[10252670] |The [[Charlie Chaplin]] film ''[[The Great Dictator]]'' (1940) showed [[Warsaw ghetto|Jewish ghetto]] shops designated in Esperanto, each with the general Esperanto suffix ''-ejo'' (meaning "place for..."), in order to convey the atmosphere of some 'foreign' [[Eastern Europe|East European]] country without referencing any particular East European language.
[10252680] |Two full-length [[feature film]]s have been produced with [[dialogue]] entirely in Esperanto: ''[[Angoroj]],'' in 1964, and ''[[Incubus (1965 film)|Incubus]],'' a 1965 [[B-movie]] horror film.
[10252690] |[[Canada|Canadian]] actor [[William Shatner]] learned Esperanto to a limited level so that he could star in ''Incubus''.
[10252700] |Other amateur productions have been made, such as a dramatisation of the novel ''Gerda Malaperis'' (Gerda Has Disappeared).
[10252710] |A number of "mainstream" films in national languages have used Esperanto in some way, such as ''[[Gattaca]]'' (1997), in which Esperanto can be overheard on the public address system.
[10252720] |In the 1994 film ''[[Street Fighter]]'', Esperanto is the native language of the fictional country of [[Shadaloo]], and in a barracks scene the soldiers of villain [[M. Bison]] sing a rousing Russian Army-style chorus, the "Bison Troopers Marching Song", in the language.
[10252730] |Esperanto is also spoken and appears on signs in the film ''[[Blade: Trinity]]''.
[10252740] |In the British comedy ''[[Red Dwarf]]'', [[Arnold Rimmer]] is seen attempting to learn Esperanto in a number of early episodes, including ''[[Kryten (Red Dwarf episode)|Kryten]]''.
[10252750] |In the first season, signs on the titular spacecraft are in both English and Esperanto.
[10252760] |Esperanto is used as the universal language in the far future of [[Harry Harrison]]'s ''[[Stainless Steel Rat]]'' and ''[[Deathworld]]'' stories.
[10252770] |In a 1969 guest appearance on ''[[The Tonight Show]]'', [[Jay Silverheels]] of ''[[The Lone Ranger]]'' fame appeared in character as [[Tonto]] for a comedy sketch with [[Johnny Carson]], and claimed Esperanto skills as he sought new employment.
[10252780] |The sketch ended with a statement of his ideal situation: "Tonto, to [[Toronto, Canada|Toronto]], for Esperanto, and pronto!"
[10252790] |Also, in the [[Danny Phantom]] Episode, "Public Enemies", Danny, Tucker, and Sam come across a ghost wolf who speaks Esperanto, but only Tucker can understand at first.
[10252800] |=== In Science === 
[10252810] |In 1921 the [[French Academy of Sciences]] recommended using Esperanto for international scientific communication.
[10252820] |A few scientists and mathematicians, such as [[Maurice René Fréchet|Maurice Fréchet]] (mathematics), [[John C. Wells]] (linguistics), [[Helmar Frank]] (pedagogy and cybernetics), and [[Nobel Prize in Economics|Nobel laureate]] [[Reinhard Selten]] (economics) have published part of their work in Esperanto.
[10252830] |Frank and Selten were among the founders of the [[Akademio Internacia de la Sciencoj San Marino|International Academy of Sciences]] in [[San Marino]], sometimes called the "Esperanto University", where Esperanto is the primary language of teaching and administration.
[10252840] |=== Goals of the movement === 
[10252850] |Zamenhof's intention was to create an easy-to-learn language to foster international understanding.
[10252860] |It was to serve as an international auxiliary language, that is, as a universal second language, not to replace ethnic languages.
[10252870] |This goal was widely shared among Esperanto speakers in the early decades of the movement.
[10252880] |Later, Esperanto speakers began to see the language and the culture that had grown up around it as ends in themselves, even if Esperanto is never adopted by the United Nations or other international organizations.
[10252890] |Those Esperanto speakers who want to see Esperanto adopted officially or on a large scale worldwide are commonly called ''[[Finvenkismo|finvenkistoj]]'', from ''fina venko'', meaning "final victory", or ''pracelistoj'', from ''pracelo'', meaning "original goal".
[10252900] |Those who focus on the intrinsic value of the language are commonly called ''[[Raumism|raŭmistoj]]'', from [[Rauma, Finland|Rauma]], [[Finland]], where a declaration on the near-term unlikelihood of the "fina venko" and the value of Esperanto culture was made at the International Youth Congress in 1980.
[10252910] |These categories are, however, not mutually exclusive.
[10252920] |The [[Prague Manifesto (Esperanto)|Prague Manifesto]] (1996) presents the views of the mainstream of the Esperanto movement and of its main organisation, the World Esperanto Association ([[World Esperanto Association|UEA]]).
[10252930] |=== Symbols and flags === 
[10252940] |In 1893, C. Rjabinis and P. Deullin designed and manufactured a lapel pin for Esperantists to identify each other.
[10252950] |The design was a circular pin with a white background and a five pointed green star.
[10252960] |The theme of the design was the hope of the [[Continent#Number of continents|five continents]] being united by a common language.
[10252970] |The earliest flag, and the one most commonly used today, features a green five-pointed star against a white canton, upon a field of green.
[10252980] |It was proposed to Zamenhof by [[Ireland|Irishman]] Richard Geoghegan, author of the first Esperanto textbook for English speakers, in 1887.
[10252990] |In 1905, delegates to the first conference of Esperantists at Boulogne-sur-Mer unanimously approved a version that differed from the modern flag only by the superimposition of an "E" over the green star.
[10253000] |Other variants include that for Christian Esperantists, with a white [[Christian cross]] superimposed upon the green star, and that for Leftists, with [[Red flag|the color of the field changed from green to red]].
[10253010] |In 1987, a second flag design was chosen in a contest organized by the UEA celebrating the first centennial of the language.
[10253020] |It featured a white background with two stylised curved "E"s facing each other.
[10253030] |Dubbed the "jubilea simbolo" ([[Esperanto jubilee symbol|jubilee symbol]]) , it attracted criticism from some Esperantists, who dubbed it the "melono" (melon) because of the design's elliptical shape.
[10253040] |It is still in use, though to a lesser degree than the traditional symbol, known as the "verda stelo" (green star).
[10253050] |=== Religion === 
[10253060] |Esperanto has served an important role in several religions, such as [[Oomoto]] from Japan and [[Baha'i]] from Iran, and has been encouraged by others.
[10253070] |==== Oomoto ==== 
[10253080] |The [[Oomoto]] religion encourages the use of Esperanto among their followers and includes Zamenhof as one of its deified spirits.
[10253090] |==== Bahá'í Faith==== 
[10253100] |The [[Bahá'í Faith]] encourages the [[Bahá'í Faith and auxiliary language|use of an auxiliary international language]].
[10253110] |While endorsing no specific language, some Bahá'ís see Esperanto as having great potential in this role.
[10253120] |[[Lidja Zamenhof]], the daughter of Esperanto founder [[L. L. Zamenhof]], became a Bahá'í.
[10253130] |Various volumes of the [[Bahá'í literature]]s and other Baha'i books have been translated into Esperanto.
[10253140] |==== Spiritism ==== 
[10253150] |Esperanto is also actively promoted, at least in [[Brazil]], by followers of [[Spiritism]].
[10253160] |The Brazilian Spiritist Federation publishes Esperanto coursebooks, translations of [[Spiritist Codification|Spiritism's basic books]], and encourages Spiritists to become Esperantists.
[10253170] |==== Bible translations ==== 
[10253180] |The first translation of the [[Bible]] into Esperanto was a translation of the [[Tanach]] or Old Testament done by [[L. L. Zamenhof]].
[10253190] |The translation was reviewed and compared with other languages' translations by a group of British clergy and scholars before publishing it at the [[British and Foreign Bible Society]] in 1910.
[10253200] |In 1926 this was published along with a New Testament translation, in an edition commonly called the "Londona Biblio".
[10253210] |In the 1960s, the ''Internacia Asocio de Bibliistoj kaj Orientalistoj'' tried to organize a new, ecumenical Esperanto Bible version.
[10253220] |Since then, the Dutch Lutheran pastor Gerrit Berveling has translated the [[Deuterocanonical]] or apocryphal books in addition to new translations of the Gospels, some of the New Testament epistles, and some books of the Tanakh or Old Testament.
[10253230] |These have been published in various separate booklets, or serialized in ''Dia Regno'', but the [[Deuterocanonical]] books have appeared in recent editions of the Londona Biblio.
[10253240] |==== Christianity ==== 
[10253250] |Two Roman Catholic popes, [[Pope John Paul II|John Paul II]] and [[Pope Benedict XVI|Benedict XVI]], have regularly used Esperanto in their multilingual ''[[urbi et orbi]]'' blessings at Easter and Christmas each year since Easter 1994.
[10253260] |Christian Esperanto organizations include two that were formed early in the history of Esperanto, the [[International Union of Catholic Esperantists]] and the [[List of Esperanto organizations#Religion|International Christian Esperantists League]].
[10253270] |An issue of "The Friend" describes the activities of the [[Quaker]] Esperanto Society.
[10253280] |There are instances of Christian apologists and teachers who use Esperanto as a medium.
[10253290] |[[Nigeria]]n [[Pastor]] Bayo Afolaranmi's "[http://groups.yahoo.com/group/spiritanutrajxo/ Spirita nutraĵo]" (spiritual food) Yahoo mailing list, for example, has hosted weekly messages since 2003.
[10253300] |[[Chick Publications]], publisher of [[Fundamentalist Christianity|Protestant fundamentalist]] themed evangelistic tracts, has published a number of comic book style tracts by [[Jack T. Chick]] translated into Esperanto, including "This Was Your Life!"
[10253310] |("Jen Via Tuto Vivo!")
[10253320] |==== Islam ==== 
[10253330] |[[Ayatollah Khomeini]] of [[Iran]] called on Muslims to learn Esperanto and praised its use as a medium for better understanding among peoples of different religious backgrounds.
[10253340] |After he suggested that Esperanto replace English as an international [[lingua franca]], it began to be used in the seminaries of [[Qom]].
[10253350] |An Esperanto translation of the [[Qur'an]] was published by the state shortly thereafter.
[10253360] |In 1981, Khomeini and the Iranian government began to oppose Esperanto after realising that followers of the [[Bahá'í Faith]] were interested in it.
[10253370] |== Criticism == 
[10253380] |Esperanto was conceived as a language of international communication, more precisely as a universal [[second language]].
[10253390] |Since publication, there has been debate over whether it is possible for Esperanto to attain this position, and whether it would be an improvement for international communication if it did.
[10253400] |There have been a number of attempts to reform the language, the most well-known of which is the language [[Ido]] which resulted in a schism in the community at the time, beginning in 1907.
[10253410] |Since Esperanto is a planned language, there have been many, often passionate, criticisms of minor points which are too numerous to cover here, such as Zamenhof's choice of the word ''edzo'' over something like ''spozo'' for "husband, spouse", or his choice of the Classic Greek and Old Latin singular and plural endings ''-o, -oj, -a, -aj'' over their Medieval contractions ''-o, -i, -a, -e.''
[10253420] |(Both these changes were adopted by the Ido reform, though Ido dispensed with adjectival agreement altogether.)
[10253430] |See the links [[Esperanto#Criticism|below]] for examples of more general criticism.
[10253440] |The more common points include: 
[10253450] |* Esperanto has failed the expectations of its founder to become a universal second language.
[10253460] |Although many promoters of Esperanto stress the few successes it has had, the fact remains that well over a century since its publication, the portion of the world that speaks Esperanto, and the number of primary and secondary schools which teach it, remain minuscule.
[10253470] |It simply cannot compete with English in this regard.
[10253480] |* The vocabulary and grammar are based on major European languages, and are not universal.
[10253490] |Often this criticism is specific to a few points such as adjectival agreement and the accusative case (generally such obvious details are all that reform projects suggest changing), but sometimes it is more general: Both the grammar and the 'international' vocabulary are difficult for many Asians, among others, and give an unfair advantage to speakers of European languages.
[10253500] |One attempt to address this issue is [[Lojban]], which draws from the six populous languages [[Arabic language|Arabic]], [[Chinese language|Chinese]], [[English language|English]], [[Hindi]], [[Russian language|Russian]], and [[Spanish language|Spanish]], and whose grammar is designed for computer parsing.
[10253510] |* The vocabulary, diacritic letters, and grammar are too dissimilar from the major Western European languages, and therefore Esperanto is not as easy as it could be for speakers of those languages to learn.
[10253520] |Attempts to address this issue include the younger planned languages [[Ido]] and [[Interlingua]].
[10253530] |* Esperanto phonology is unimaginatively provincial, being essentially [[Belorussian language|Belorussian]] with regularized stress, leaving out only the [[nasal vowel]]s, [[palatalization|palatalized consonants]], and /dz/.
[10253540] |For example, Esperanto has phonemes such as {{IPA|/x/, /ʒ/, /ts/, /eu̯/}} ''(ĥ, ĵ, c, eŭ)'' which are rare as distinct phonemes outside Europe.
[10253550] |(Note that none of these are found in initial position in English.)
[10253560] |* Esperanto has no culture.
[10253570] |Although it has a large international literature, Esperanto does not encapsulate a specific culture.
[10253580] |* Esperanto is culturally European.
[10253590] |This is due to the European derivation of its vocabulary, and more insidiously, its [[semantics]]; both infuse the language with a European world view.
[10253600] |* The vocabulary is too large.
[10253610] |Rather than deriving new words from existing roots, large numbers of new roots are adopted into the language by people who think they're international, when in fact they're only European.
[10253620] |This makes the language much more difficult for non-Europeans than it needs to be.
[10253630] |* Esperanto is [[sexism|sexist]].
[10253640] |As in English, there is no neutral pronoun for ''s/he,'' and most kin terms and titles are masculine by default and only feminine when so specified.
[10253650] |There have been many attempts to address this issue, of which one of the better known is [[Riism]].
[10253660] |* Esperanto is, looks, or sounds artificial.
[10253670] |This criticism is primarily due to the letters with circumflex diacritics, which some find odd or cumbersome, and to the lack of fluent speakers: Few Esperantists have spent much time with fluent, let alone native, speakers, and many learn Esperanto relatively late in life, and so speak haltingly, which can create a negative impression among non-speakers.
[10253680] |Among fluent speakers, Esperanto sounds no more artificial than any other language.
[10253690] |Others claim that an artificial language will necessarily be deficient, due to its very nature, but the [[Hungarian Academy of Sciences]] has found that Esperanto fulfills all the requirements of a living language.
[10253700] |== Modifications == 
[10253710] |Though Esperanto itself has changed little since the publication of the ''[[Fundamento de Esperanto]]'' (Foundation of Esperanto), a number of reform projects have been proposed over the years, starting with [[Reformed Esperanto|Zamenhof's proposals in 1894]] and [[Ido]] in 1907.
[10253720] |Several later constructed languages, such as Fasile, were based on Esperanto.
[10253730] |In modern times, attempts have been made to eliminate perceived sexism in the language.
[10253740] |One example of this is [[Riism]].
[10253750] |However, as Esperanto has become a living language, changes are as difficult to implement as in ethnic languages.
[10260010] |<article>Formal grammar</article>
[10260020] |In [[formal semantics]], [[computer science]] and [[linguistics]], a '''formal grammar''' (also called '''formation rules''') is a precise description of a [[formal language]] &ndash; that is, of a [[set]] of [[String (computer science)|strings]] over some [[Alphabet (computer science)|alphabet]].
[10260030] |In other words, a grammar describes which of the possible sequences of symbols (strings) in a language constitute valid words or statements in that language, but it does not describe their [[semantics]] (i.e. what they mean).
[10260040] |The branch of mathematics that is concerned with the properties of formal grammars and languages is called [[formal language theory]].
[10260050] |A grammar is usually regarded as a means to [[generate]] all the valid strings of a language; it can also be used as the basis for a [[recognizer]] that determines for any given string whether it is [[grammatical]] (i.e. belongs to the language).
[10260060] |To describe such recognizers, formal language theory uses separate formalisms, known as [[automata theory|automata]].
[10260070] |A grammar can also be used to [[analyze]] the strings of a language &ndash; i.e. to describe their internal structure.
[10260080] |In computer science, this process is known as [[parsing]].
[10260090] |Most languages have very [[compositional semantics]], i.e. the meaning of their utterances is structured according to their [[syntax]]; therefore, the first step to describing the meaning of an utterance in language is to analyze it and look at its analyzed form (known as its [[parse tree]] in computer science, and as its [[deep structure]] in [[generative grammar]]).
[10260100] |== Background == 
[10260110] |=== Formal language === 
[10260120] |A ''formal language'' is an organized [[set]] of [[symbol]]s the essential feature of which is that it can be precisely defined in terms of just the shapes and locations of those symbols.
[10260130] |Such a language can be defined, then, without any [[reference]] to any [[meaning (linguistics)|meaning]]s of any of its expressions; it can exist before any [[formal interpretation]] is assigned to it -- that is, before it has any meaning.
[10260140] |First order logic is expressed in some formal language.
[10260150] |A formal grammar determines which symbols and sets of symbols are [[Formula (mathematical logic)|formula]]s in a formal language.
[10260160] |=== Formal systems === 
[10260170] |A ''formal system'' (also called a ''logical calculus'', or a ''logical system'') consists of a formal language together with a [[deductive apparatus]] (also called a ''deductive system'').
[10260180] |The deductive apparatus may consist of a set of [[transformation rule]]s (also called ''inference rules'') or a set of [[axiom]]s, or have both.
[10260190] |A formal system is used to [[Proof theory|derive]] one expression from one or more other expressions.
[10260200] |=== Formal proofs === 
[10260210] |A ''formal proof'' is a sequence of well-formed formulas of a formal language, the last one of which is a [[theorem]] of a formal system.
[10260220] |The theorem is a [[syntactic consequence]] of all the wffs preceding it in the proof.
[10260230] |For a wff to qualify as part of a proof, it must be the result of applying a rule of the deductive apparatus of some formal system to the previous wffs in the proof sequence.
[10260240] |=== Formal interpretations === 
[10260250] |An ''interpretation'' of a formal system is the assignment of meanings to the symbols, and truth-values to the sentences of a formal system.
[10260260] |The study of formal interpretations is called [[formal semantics]].
[10260270] |''Giving an interpretation'' is synonymous with ''constructing a [[Structure (mathematical logic)|model]].
[10260280] |== Formal grammars == 
[10260290] |A grammar mainly consists of a set of rules for transforming strings.
[10260300] |(If it ''only'' consisted of these rules, it would be a [[semi-Thue system]].)
[10260310] |To generate a string in the language, one begins with a string consisting of only a single ''start symbol'', and then successively applies the rules (any number of times, in any order) to rewrite this string.
[10260320] |The language consists of all the strings that can be generated in this manner.
[10260330] |Any particular sequence of legal choices taken during this rewriting process yields one particular string in the language.
[10260340] |If there are multiple ways of generating the same single string, then the grammar is said to be [[ambiguous grammar|ambiguous]].
[10260350] |For example, assume the alphabet consists of <math>a</math> and <math>b</math>, the start symbol is <math>S</math> and we have the following rules:
[10260360] |: 1. <math>S \rightarrow aSb</math>
[10260370] |: 2. <math>S \rightarrow ba</math>
[10260380] |then we start with <math>S</math>, and can choose a rule to apply to it.
[10260390] |If we choose rule 1, we obtain the string <math>aSb</math>.
[10260400] |If we choose rule 1 again, we replace <math>S</math> with <math>aSb</math> and obtain the string <math>aaSbb</math>.
[10260410] |This process can be repeated at will until all occurrences of ''S'' are removed, and only symbols from the alphabet remain (i.e., <math>a</math> and <math>b</math>).
[10260420] |For example, if we now choose rule 2, we replace <math>S</math> with <math>ba</math> and obtain the string <math>aababb</math>, and are done.
[10260430] |We can write this series of choices more briefly, using symbols: <math>S \Rightarrow aSb \Rightarrow aaSbb \Rightarrow aababb</math>.
[10260440] |The language of the grammar is the set of all the strings that can be generated using this process: <math>\left \{ba, abab, aababb, aaababbb, ...\right \}</math>.
[10260450] |=== Formal definition === 
[10260460] |In the classic formalization of generative grammars first proposed by [[Noam Chomsky]] in the 1950s, a grammar ''G'' consists of the following components: 
[10260470] |* A finite set <math>N</math> of ''[[nonterminal symbol]]s''.
[10260480] |* A finite set <math>\Sigma</math> of ''[[terminal symbol]]s'' that is [[Disjoint sets|disjoint]] from <math>N</math>.
[10260490] |* A finite set <math>P</math> of ''production rules'', each of the form
[10260500] |:: <math>(\Sigma \cup N)^{*} N (\Sigma \cup N)^{*} \rightarrow (\Sigma \cup N)^{*} </math> 
[10260510] |:where <math>{}^{*}</math> is the [[Kleene star]] operator and <math>\cup</math> denotes [[union (set theory)|set union]].
[10260520] |That is, each production rule maps from one string of symbols to another, where the first string contains at least one nonterminal symbol.
[10260530] |In the case that the second string is the [[empty string]] &ndash; that is, that it contains no symbols at all &ndash; in order to avoid confusion, the empty string is often denoted with a special notation, often (<math>\lambda</math>, <math>e</math> or <math>\epsilon</math>.
[10260540] |* A distinguished symbol <math>S \in N</math> that is the ''start symbol''.
[10260550] |A grammar is formally defined as the ordered quad-tuple <math>(N, \Sigma, P, S)</math>.
[10260560] |Such a formal grammar is often called a ''rewriting system'' or a ''phrase structure grammar'' in the literature.
[10260570] |The operation of a grammar can be defined in terms of relations on strings: 
[10260580] |* Given a grammar <math>G = (N, \Sigma, P, S)</math>, the binary relation <math>\Rightarrow_G</math> (pronounced as "G derives in one step") on strings in <math>(\Sigma \cup N)^{*}</math> is defined by:
[10260590] |<math>x \Rightarrow_G y \mbox{ iff } \exists u, v, w \in \Sigma^*, X \in N: x = uXv \wedge y = uwv \wedge X \rightarrow w \in P</math> 
[10260600] |* the relation <math>{\Rightarrow_G}^*</math> (pronounced as ''G derives in zero or more steps'') is defined as the [[transitive closure]] of <math>(\Sigma \cup N)^{*}</math>
[10260610] |* the ''language'' of <math>G</math>, denoted as <math>\boldsymbol{L}(G)</math>, is defined as all those strings over <math>\Sigma</math> that can be generated by starting with the start symbol <math>S</math> and then applying the production rules in <math>P</math> until no more nonterminal symbols are present; that is, the set <math>\{ w \in \Sigma^* \mid S {\Rightarrow_G}^* w \}</math>.
[10260620] |Note that the grammar <math>G = (N, \Sigma, P, S)</math> is effectively the [[semi-Thue system]] <math>(N \cup \Sigma, P)</math>, rewriting strings in exactly the same way; the only difference is in that we distinguish specific ''nonterminal'' symbols which must be rewritten in rewrite rules, and are only interested in rewritings from the designated start symbol <math>S</math> to strings without nonterminal symbols.
[10260630] |=== Example === 
[10260640] |''For these examples, formal languages are specified using [[set-builder notation]].''
[10260650] |Consider the grammar <math>G</math> where <math>N = \left \{S, B\right \}</math>, <math>\Sigma = \left \{a, b, c\right \}</math>, <math>S</math> is the start symbol, and <math>P</math> consists of the following production rules:
[10260660] |: 1. <math>S \rightarrow aBSc</math>
[10260670] |: 2. <math>S \rightarrow abc</math>
[10260680] |: 3. <math>Ba \rightarrow aB</math>
[10260690] |: 4. <math>Bb \rightarrow bb </math>
[10260700] |Some examples of the derivation of strings in <math>\boldsymbol{L}(G)</math> are: 
[10260710] |* <math>\boldsymbol{S} \Rightarrow_2 \boldsymbol{abc}</math>
[10260720] |* <math>\boldsymbol{S} \Rightarrow_1 \boldsymbol{aBSc} \Rightarrow_2 aB\boldsymbol{abc}c \Rightarrow_3 a\boldsymbol{aB}bcc \Rightarrow_4 aa\boldsymbol{bb}cc</math>
[10260730] |* <math>\boldsymbol{S} \Rightarrow_1 \boldsymbol{aBSc} \Rightarrow_1 aB\boldsymbol{aBSc}c \Rightarrow_2 aBaB\boldsymbol{abc}cc \Rightarrow_3 a\boldsymbol{aB}Babccc \Rightarrow_3 aaB\boldsymbol{aB}bccc </math><math> \Rightarrow_3 aa\boldsymbol{aB}Bbccc \Rightarrow_4 aaaB\boldsymbol{bb}ccc \Rightarrow_4 aaa\boldsymbol{bb}bccc</math>
[10260740] |:(Note on notation: <math>L \Rightarrow_i R</math> reads "''L'' generates ''R'' by means of production ''i''" and the generated part is each time indicated in bold.)
[10260750] |This grammar defines the language <math>L = \left \{ a^{n}b^{n}c^{n} | n \ge 1 \right \}</math> where <math>a^{n}</math> denotes a string of ''n'' consecutive <math>a</math>'s.
[10260760] |Thus, the language is the set of strings that consist of 1 or more <math>a</math>'s, followed by the same number of <math>b</math>'s, followed by the same number of <math>c</math>'s.
[10260770] |=== The Chomsky hierarchy === 
[10260780] |When [[Noam Chomsky]] first formalized generative grammars in 1956, he classified them into types now known as the [[Chomsky hierarchy]].
[10260790] |The difference between these types is that they have increasingly strict production rules and can express fewer formal languages.
[10260800] |Two important types are ''[[context-free grammar]]s'' (Type 2) and ''[[regular grammar]]s'' (Type 3).
[10260810] |The languages that can be described with such a grammar are called ''[[context-free language]]s'' and ''[[regular language]]s'', respectively.
[10260820] |Although much less powerful than unrestricted grammars (Type 0), which can in fact express any language that can be accepted by a [[Turing machine]], these two restricted types of grammars are most often used because [[parsing|parser]]s for them can be efficiently implemented.
[10260830] |For example, all regular languages can be recognized by a [[finite state machine]], and for useful subsets of context-free grammars there are well-known algorithms to generate efficient [[LL parser]]s and [[LR parser]]s to recognize the corresponding languages those grammars generate.
[10260840] |==== Context-free grammars ==== 
[10260850] |A ''[[context-free grammar]]'' is a grammar in which the left-hand side of each production rule consists of only a single nonterminal symbol.
[10260860] |This restriction is non-trivial; not all languages can be generated by context-free grammars.
[10260870] |Those that can are called ''context-free languages''.
[10260880] |The language defined above is not a context-free language, and this can be strictly proven using the [[pumping lemma for context-free languages]], but for example the language <math>\left \{ a^{n}b^{n} | n \ge 1 \right \}</math> (at least 1 <math>a</math> followed by the same number of <math>b</math>'s) is context-free, as it can be defined by the grammar <math>G_2</math> with <math>N=\left \{S\right \}</math>, <math>\Sigma=\left \{a,b\right \}</math>, <math>S</math> the start symbol, and the following production rules:
[10260890] |: 1. <math>S \rightarrow aSb</math>
[10260900] |: 2. <math>S \rightarrow ab</math>
[10260910] |A context-free language can be recognized in <math>O(n^3)</math> time (''see'' [[Big O notation]]) by an algorithm such as [[Earley's algorithm]].
[10260920] |That is, for every context-free language, a machine can be built that takes a string as input and determines in <math>O(n^3)</math> time whether the string is a member of the language, where <math>n</math> is the length of the string.
[10260930] |Further, some important subsets of the context-free languages can be recognized in linear time using other algorithms.
[10260940] |==== Regular grammars ==== 
[10260950] |In [[regular grammar]]s, the left hand side is again only a single nonterminal symbol, but now the right-hand side is also restricted: It may be the empty string, or a single terminal symbol, or a single terminal symbol followed by a nonterminal symbol, but nothing else.
[10260960] |(Sometimes a broader definition is used: one can allow longer strings of terminals or single nonterminals without anything else, making languages [[syntactic sugar|easier to denote]] while still defining the same class of languages.)
[10260970] |The language defined above is not regular, but the language <math>\left \{ a^{n}b^{m} \,| \, m,n \ge 1 \right \}</math> (at least 1 <math>a</math> followed by at least 1 <math>b</math>, where the numbers may be different) is, as it can be defined by the grammar <math>G_3</math> with <math>N=\left \{S, A,B\right \}</math>, <math>\Sigma=\left \{a,b\right \}</math>, <math>S</math> the start symbol, and the following production rules:
[10260980] |:# <math>S \rightarrow aA</math>
[10260990] |:# <math>A \rightarrow aA</math>
[10261000] |:# <math>A \rightarrow bB</math>
[10261010] |:# <math>B \rightarrow bB</math>
[10261020] |:# <math>B \rightarrow \epsilon</math>
[10261030] |All languages generated by a regular grammar can be recognized in linear time by a [[finite state machine]].
[10261040] |Although, in practice, regular grammars are commonly expressed using [[regular expression]]s, some forms of regular expression used in practice do not strictly generate the regular languages and do not show linear recognitional performance due to those deviations.
[10261050] |=== Other forms of generative grammars === 
[10261060] |Many extensions and variations on Chomsky's original hierarchy of formal grammars have been developed more recently, both by linguists and by computer scientists, usually either in order to increase their expressive power or in order to make them easier to analyze or [[parsing|parse]].
[10261070] |Some forms of grammars developed include:
[10261080] |* [[Tree-adjoining grammar]]s increase the expressiveness of conventional generative grammars by allowing rewrite rules to operate on [[parse tree]]s instead of just strings.
[10261090] |* [[Affix grammar]]s and [[attribute grammar]]s allow rewrite rules to be augmented with semantic attributes and operations, useful both for increasing grammar expressiveness and for constructing practical language translation tools.
[10261100] |== Analytic grammars == 
[10261110] |Though there is very little literature on [[parsing]] [[algorithms]], most of these algorithms assume that the language to be parsed is initially ''described'' by means of a ''generative'' formal grammar, and that the goal is to transform this generative grammar into a working parser.
[10261120] |Strictly speaking, a generative grammar does not in any way correspond to the algorithm used to parse a language, and various algorithms have different restrictions on the form of production rules that are considered well-formed.
[10261130] |An alternative approach is to formalize the language in terms of an analytic grammar in the first place, which more directly corresponds to the structure and semantics of a parser for the language.
[10261140] |Examples of analytic grammar formalisms include the following:
[10261150] |* [[The Language Machine]] directly implements unrestricted analytic grammars.
[10261160] |Substitution rules are used to transform an input to produce outputs and behaviour.
[10261170] |The system can also produce [http://languagemachine.sourceforge.net/picturebook.html the lm-diagram] which shows what happens when the rules of an unrestricted analytic grammar are being applied.
[10261180] |* [[Top-down parsing language]] (TDPL): a highly minimalist analytic grammar formalism developed in the early 1970s to study the behavior of [[Top-down parsing|top-down parsers]].
[10261190] |* [[Link grammar]]s: a form of analytic grammar designed for [[linguistics]], which derives syntactic structure by examining the positional relationships between pairs of words.
[10261200] |* [[Parsing expression grammar]]s (PEGs): a more recent generalization of TDPL designed around the practical [[expressiveness]] needs of [[programming language]] and [[compiler]] writers.
[10270010] |<article>Free software</article>
[10270020] |'''Free software''' or software libre is [[software]] that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with minimal restrictions only to ensure that further recipients can also do these things.
[10270030] |In practice, for software to be distributed as free software, the human readable form of the program (the "[[source code]]") must be made available to the recipient along with a notice granting the above permissions.
[10270040] |Such a notice is a "[[free software licence]]", or, in theory, could be a notice saying that the source code is released into the [[public domain]].
[10270050] |The [[free software movement]] was conceived in 1983 by [[Richard Stallman]] to make these freedoms available to every computer user.
[10270060] |From the late 1990s onward, [[alternative terms for free software]] came into use.
[10270070] |"'''[[Open source software]]'''" is the most common such alternative term.
[10270080] |Others include "'''software [[Gratis versus Libre|libre]]'''", "free, libre and open-source software" ("'''[[FOSS]]'''", or, with "libre", "'''FLOSS'''").
[10270090] |The antonym of free software is "''[[proprietary software]]''" or ''non-free software''.
[10270100] |Free software is distinct from "[[freeware]]" which is [[proprietary software]] made available free of charge.
[10270110] |Users usually cannot study, modify, or redistribute freeware.
[10270120] |Since free software may be freely redistributed, it generally is available at little or no cost.
[10270130] |Free software business models are usually based on adding value such as support, training, customization, integration, or certification.
[10270140] |At the same time, some business models which work with [[proprietary software]] are not compatible with free software, such as those that depend on a user paying for a licence in order to lawfully use a software product.
[10270150] |== History == 
[10270160] |In the 1950s, 1960s, and 1970s, it was normal for computer users to have the freedoms that are provided by free software.
[10270170] |[[Software]] was commonly shared by individuals who used computers and by hardware manufacturers who were glad that people were making software that made their hardware useful.
[10270180] |In the 1970s and early 1980s, the [[software industry]] began using technical measures (such as only distributing [[Executable|binary copies]] of [[computer programs]]) to prevent [[computer users]] from being able to study and modify software..
[10270190] |In 1980 [[copyright]] law was extended to computer programs.
[10270200] |In 1983, [[Richard Stallman]], longtime member of the [[hacker (free and open source software)|hacker]] community at the [[MIT Artificial Intelligence Laboratory]], announced the [[GNU project]], saying that he had become frustrated with the effects of the change in culture of the computer industry and its users.
[10270210] |Software development for the [[GNU operating system]] began in January 1984, and the [[Free Software Foundation]] (FSF) was founded in October 1985.
[10270220] |He developed a free software definition and the concept of "[[copyleft]]", designed to ensure software freedom for all.
[10270230] |Free software is a widespread international concept, producing software used by individuals, large organizations, and governmental administrations.
[10270240] |Free software has a very high market penetration in server-side Internet applications such as the [[Apache web server]], [[MySQL]] database, and [[PHP]] scripting language.
[10270250] |Completely free computing environments are available as large packages of basic system software, such as the many [[GNU/Linux distribution]]s and [[FreeBSD]].
[10270260] |Free software [[Software development|developers]] have also created free versions of almost all commonly used desktop applications, including Web browsers, office productivity suites, and multimedia players.
[10270270] |It is important to note, however, that in many categories, free software for individual [[workstation]]s or home users has only a fraction of the market share of its proprietary competitors.
[10270280] |Most free software is distributed [[online]] without charge, or [[off-line]] at the [[marginal cost]] of distribution, but this pricing model is not required, and people may sell copies of free software programs for any price.
[10270290] |The economic viability of free software has been recognised by large corporations such as [[IBM]], [[Red Hat]], and [[Sun Microsystems]].
[10270300] |Many companies whose core business is not in the IT sector choose free software for their Internet information and sales sites, due to the lower initial capital investment and ability to freely customize the application packages.
[10270310] |Also, some non-software industries are beginning to use techniques similar to those used in free software development for their research and development process; scientists, for example, are looking towards more open development processes, and hardware such as microchips are beginning to be developed with specifications released under [[copyleft]] licenses (see the [[OpenCores]] project, for instance).
[10270320] |[[Creative Commons]] and the [[free culture movement]] have also been largely influenced by the free software movement.
[10270330] |===Naming=== 
[10270340] |The FSF recommends using the term "free software" rather than "open source software" because that term and the associated marketing campaign focuses on the technical issues of software development, avoiding the issue of user freedoms.
[10270350] |"[[Libre]]" is used to avoid the ambiguity of the word "free".
[10270360] |However, amongst English speakers, ''libre'' is primarily only used within the free software movement.
[10270370] |== Definition == 
[10270380] |The first formal definition of free software was published by FSF in February 1986.
[10270390] |That definition, written by Richard Stallman, is still maintained today and states that software is free software if people who receive a copy of the software have the following four freedoms:
[10270400] |* Freedom 0: The freedom to run the program for any purpose.
[10270410] |* Freedom 1: The freedom to study and modify the program.
[10270420] |* Freedom 2: The freedom to copy the program so you can help your neighbor.
[10270430] |* Freedom 3: The freedom to improve the program, and release your improvements to the public, so that the whole community benefits.
[10270440] |Freedoms 1 and 3 require [[source code]] to be available because studying and modifying software without its source code is highly impractical.
[10270450] |Thus, free software means that [[user (computing)|computer users]] have the freedom to cooperate with whom they choose, and to control the software they use.
[10270460] |To summarize this into a remark distinguishing ''[[Gratis versus Libre|libre]]'' (freedom) software from ''[[Gratis versus Libre|gratis]]'' (zero price) software, [[Richard Stallman]] said: "''Free software is a matter of liberty, not price.
[10270470] |To understand the concept, you should think of 'free' as in '[[free speech]]', not as in '[[free beer]]<nowiki>'</nowiki>''".
[10270480] |In the late 90s, other groups published their own definitions which describe an almost identical set of software.
[10270490] |The most notable are [[Debian Free Software Guidelines]] published in 1997, and the [[Open Source Definition]], published in 1998.
[10270500] |The BSD-based operating systems, such as [[FreeBSD]], [[OpenBSD]], and [[NetBSD]], do not have their own formal definitions of free software.
[10270510] |Users of these systems generally find the same set of software to be acceptable, but sometimes see copyleft as restrictive.
[10270520] |They generally advocate [[permissive free software licenses]], which allow others to make software based on their source code, and then release the modified result as proprietary software.
[10270530] |Their view is that this permissive approach is more free.
[10270540] |The [[Kerberos (protocol)|Kerberos]], [[X.org]], and [[Apache License|Apache]] software licenses are substantially similar in intent and implementation.
[10270550] |All of these software packages originated in academic institutions interested in wide technology transfer ([[University of California]], [[Massachusetts Institute of Technology|MIT]], and [[University of Illinois at Urbana-Champaign|UIUC]]).
[10270560] |== Examples of free software == 
[10270570] |The [[Free Software Directory]] is a free software project that maintains a large database of free software packages.
[10270580] |===Notable free software=== 
[10270590] |* [[Graphical user interface|GUI]] related
[10270600] |**[[X Window System]]
[10270610] |**[[GNOME]]
[10270620] |**[[KDE]]
[10270630] |**[[Xfce]] desktop environments
[10270640] |* [[OpenOffice.org]] office suite
[10270650] |* [[Mozilla Application Suite|Mozilla]] and [[Mozilla Firefox|Firefox]] web browsers.
[10270660] |* Typesetting and document preparation systems
[10270670] |**[[TeX]]
[10270680] |**[[LaTeX]]
[10270690] |* Graphics tools like [[GIMP]] image graphics editor and [[Blender (software)|Blender]] 3D animation program.
[10270700] |* [[Text editor]]s like [[vi]] or [[emacs]].
[10270710] |* [[ogg]] is a free software multimedia container, used to hold [[ogg vorbis]] sound and [[ogg theora]] video.
[10270720] |* [[Relational database]] systems
[10270730] |**[[MySQL]]
[10270740] |**[[PostgreSQL]]
[10270750] |* [[GNU Compiler Collection|GCC]] compilers, [[GDB]] debugger and the [[GNU C Library]].
[10270760] |====Programming languages==== 
[10270770] |*[[Java (programming language)|Java]]
[10270780] |*[[Perl]]
[10270790] |*[[PHP]]
[10270800] |*[[Python (programming language)|Python]]
[10270810] |*[[Lua (programming language)|Lua]]
[10270820] |*[[Ruby programming language|Ruby]]
[10270830] |*[[Tcl]]
[10270840] |====Servers==== 
[10270850] |*[[Apache HTTP Server|Apache web server]]
[10270860] |*[[BIND]] name server
[10270870] |*[[Sendmail]] mail transport
[10270880] |*[[Samba software|Samba]] file server.
[10270890] |====Operating systems==== 
[10270900] |*[[GNU/Linux]]
[10270910] |*[[Berkeley Software Distribution|BSD]]
[10270920] |*[[Darwin (operating system)|Darwin]]
[10270930] |*[[OpenSolaris]]
[10270940] |== Free software licenses == 
[10270950] |All free software licenses must grant people all the freedoms discussed above.
[10270960] |However, unless the applications' licenses are compatible, combining programs by mixing source code or directly linking binaries is problematic, because of license technicalities.
[10270970] |Programs indirectly connected together may avoid this problem.
[10270980] |The majority of free software uses a small set of licenses.
[10270990] |The most popular of these licenses are:
[10271000] |* the [[GNU General Public License]]
[10271010] |* the [[GNU Lesser General Public License]]
[10271020] |* the [[BSD License]]
[10271030] |* the [[Mozilla Public License]]
[10271040] |* the [[MIT License]]
[10271050] |* the [[Apache License]]
[10271060] |The Free Software Foundation and the Open Source Initiative both publish lists of licenses that they find to comply with their own definitions of free software and open-source software respectively.
[10271070] |* [[List of FSF approved software licenses]]
[10271080] |* [[List of OSI approved software licenses]]
[10271090] |These lists are necessarily incomplete, because a license need not be known by either organization in order to provide these freedoms.
[10271100] |Apart from these two organizations, the [[Debian]] project is seen by some to provide useful advice on whether particular licenses comply with their [[Debian Free Software Guidelines]].
[10271110] |Debian doesn't publish a list of ''approved'' licenses, so its judgments have to be tracked by checking what software they have allowed into their software archives.
[10271120] |That is summarized at the Debian web site.
[10271130] |However, it is rare that a license is announced as being in-compliance by either FSF or OSI guidelines and not [[Vice_versa##vice_versa|vice versa]] (the [[Netscape Public License]] used for early versions of Mozilla being an exception), so exact definitions of the terms have not become hot issues.
[10271140] |=== Permissive and copyleft licenses === 
[10271150] |The FSF categorizes licenses in the following ways:
[10271160] |* [[Public domain]] software - the copyright has expired, the work was not copyrighted or the author has abandoned the copyright.
[10271170] |Since public-domain software lacks copyright protection, it may be freely incorporated into any work, whether proprietary or free.
[10271180] |* [[permissive free software licences|Permissive licenses]], also called BSD-style because they are applied to much of the software distributed with the [[Berkeley Software Distribution|BSD]] operating systems.
[10271190] |The author retains copyright solely to disclaim warranty and require proper attribution of modified works, but permits redistribution and modification in ''any'' work, even proprietary ones.
[10271200] |* [[Copyleft]] licenses, the [[GNU General Public License]] being the most prominent.
[10271210] |The author retains copyright and permits redistribution and modification provided all such redistribution is licensed under the same license.
[10271220] |Additions and modifications by others must also be licensed under the same 'copyleft' license whenever they are distributed with part of the original licensed product.
[10271230] |== Security and reliability== 
[10271240] |There is debate over the [[computer security|security]] of free software in comparison to proprietary software, with a major issue being [[security through obscurity]].
[10271250] |A popular quantitative test in computer security is using relative counting of known unpatched security flaws.
[10271260] |Generally, users of this method advise avoiding products which lack fixes for known security flaws, at least until a fix is available.
[10271270] |Some claim that this method is biased by counting more vulnerabilities for the free software, since its source code is accessible and its community is more forthcoming about what problems exist.
[10271280] |Free software advocates rebut that even if proprietary software does not have "published" flaws, flaws could still exist and possibly be known to malicious users.
[10271290] |The ability of users to view and modify the source code allows many more people to potentially analyse the code and possibly to have a higher rate of finding bugs and flaws than an average sized corporation could manage.
[10271300] |Users having access to the source code also makes creating and deploying [[spyware]] far more difficult.
[10271310] |[[David A. Wheeler]] has published research concluding that free software is quantitatively more reliable than proprietary software.
[10271320] |== Adoption == 
[10271330] |Free software played a part in the development of the Internet, the World Wide Web and the infrastructure of [[dot-com companies]].
[10271340] |Free software allows users to cooperate in enhancing and refining the programs they use; free software is a [[pure public good]] rather than a [[private good]].
[10271350] |Companies that contribute to free software can increase commercial [[innovation]] amidst the void of [[patent]] [[cross licensing]] lawsuits.
[10271360] |(See [[Mpeg2#Patent holders|mpeg2 patent holders]])
[10271370] |Under the free software business model, free software vendors may charge a fee for distribution and offer pay support and software customization services.
[10271380] |Proprietary software uses a different business model, where a customer of the proprietary software pays a fee for a license to use the software.
[10271390] |This license may grant the customer the ability to configure some or no parts of the software themselves.
[10271400] |Often some level of support is included in the purchase of proprietary software, but additional support services (especially for enterprise applications) are usually available for an additional fee.
[10271410] |Some proprietary software vendors will also customize software for a fee.
[10271420] |Free software is generally available at little to no cost and can result in permanently lower costs compared to [[proprietary software]].
[10271430] |With free software, businesses can fit software to their specific needs by changing the software themselves or by hiring programmers to modify it for them.
[10271440] |Free software often has no warranty, and more importantly, generally does not assign legal liability to anyone.
[10271450] |However, warranties are permitted between any two parties upon the condition of the software and its usage.
[10271460] |Such an agreement is made separately from the free software license.
[10271470] |== Controversies == 
[10271480] |=== Binary blobs === 
[10271490] |In 2006, [[OpenBSD]] started the first campaign against the use of [[binary blobs]], in [[kernel (computer science)|kernels]].
[10271500] |Blobs are usually freely distributable [[device driver]]s for hardware from vendors that do not reveal driver source code to users or developers.
[10271510] |This restricts the users' freedom to effectively modify the software and distribute modified versions.
[10271520] |Also, since the blobs are undocumented and may have [[computer bug|bugs]], they pose a security risk to any [[operating system]] whose kernel includes them.
[10271530] |The proclaimed aim of the campaign against blobs is to collect hardware documentation that allows developers to write free software drivers for that hardware, ultimately enabling all free operating systems to become or remain blob-free.
[10271540] |The issue of binary blobs in the [[Linux kernel]] and other device drivers motivated some developers in Ireland to launch [[gNewSense]], a GNU/Linux distribution with all the binary blobs removed.
[10271550] |The project received support from the [[Free Software Foundation]]
[10271560] |=== BitKeeper === 
[10271570] |[[Larry McVoy]] invited high-profile free software projects to use his proprietary [[versioning system]], [[BitKeeper]], free of charge, in order to attract paying users.
[10271580] |In 2002, Linux coordinator [[Linus Torvalds]] decided to use BitKeeper to develop the Linux kernel, a free software project, claiming no free software alternative met his needs.
[10271590] |This controversial decision drew criticism from several sources, including the Free Software Foundation's founder Richard Stallman.
[10271600] |Following the apparent [[reverse engineering]] of BitKeeper's protocols, McVoy withdrew permission for gratis use by free software projects, leading the Linux kernel community to develop a free software replacement in [[Git (software)|Git]].
[10271610] |=== Patent deals === 
[10271620] |In November 2006, the [[Microsoft]] and [[Novell]] software corporations announced a controversial partnership involving, among other things, patent protection for some customers of Novell under certain conditions.
[10280010] |<article>Freeware</article>
[10280020] |'''Freeware''' is computer [[software]] that is available for use at no cost or for an optional fee.
[10280030] |Freeware is often made available in a binary-only, [[proprietary software|proprietary]] form, thus making it distinct from [[free software]].
[10280040] |Proprietary freeware allows authors to contribute something for the benefit of the community, while at the same time allowing them to retain control of the source code and preserve its business potential.
[10280050] |Freeware is different from [[shareware]], where the user is obliged to pay (e.g. after some trial period or for additional functionality).
[10280060] |== History == 
[10280070] |The term ''freeware'' was coined by [[Andrew Fluegelman]] when he wanted to sell a communications program named [[PC-Talk]] that he had created but for which he did not wish to use traditional methods of distribution because of their cost.
[10280080] |Fluegelman actually distributed PC-Talk via a process now referred to as [[shareware]].
[10280090] |Current use of the term freeware does not necessarily match the original concept by Andrew Fluegelman.
[10280100] |== Criteria == 
[10280110] |The only criterion for being classified as freeware is that the software must be fully functional for an unlimited time with no monetary cost.
[10280120] |The software license may impose one or more other restrictions on the type of use including personal use, individual use, non-profit use, non-commercial use, academic use, commercial use or any combination of these.
[10280130] |For instance, the license may be "free for personal, non-commercial use."
[10280140] |Everything created with the freeware programs can be distributed at no cost (for example graphic, documents, or sounds made by user).