An international auxiliary language[A] (sometimes abbreviated as IAL or auxlang) or interlanguage is a language meant for communication between people from different nations who do not share a common first language. An auxiliary language is primarily a foreign language.
Languages of dominant societies over the centuries have served as lingua francas that sometimes approaches the international level. Latin, Greek and the Merranean Lingua Franca were used in the past, and (Standard) Arabic, Standard Chinese, English, French, Portuguese, Russian and Spanish have been used as such in recent times in many parts of the world.
However, as lingua francas are traditionally associated with the very dominance—cultural, political, and economic—that made them popular, they are often also met with resistance. For this and other reasons, some have turned to the idea of promoting an artificial or constructed language as a possible solution, by way of "auxiliary" language. The term "auxiliary" implies that it is intended to be an additional language for the people of the world, rather than to replace their native languages. Often, the term is used to refer to planned or constructed languages proposed specifically to ease international communication, such as Esperanto, Ido and Interlingua. However, it can also refer to the concept of such a language being determined by international consensus, including even a standardized natural language (e.g., International English), and has also been connected to the project of constructing a universal language.
The use of an intermediary auxiliary language (also called a "working language", "bridge language", "vehicular language" or "unifying language") to make communication possible between people not sharing a first language, in particular when it is a third language, distinct from both mother tongues, may be almost as old as language itself. Certainly they have existed since antiquity. Latin and Greek (or Koiné Greek) were the intermediary language of all areas of the Merraneum; Akkadian, and then Aramaic, remained the common languages of a large part of Western Asia through several earlier empires. Such natural languages used for communication between people not sharing the same mother tongue are called lingua francas.
Lingua francas have arisen around the globe throughout human history, sometimes for commercial reasons (so-called "trade languages") but also for diplomatic and administrative convenience, and as a means of exchanging information between scientists and other scholars of different nationalities. The term originates with one such language, Merranean Lingua Franca, a pidgin language used as a trade language in the Merranean area from the 11th to the 19th century. Examples of lingua francas remain numerous, and exist on every continent. The most obvious example as of the early 21st century is English. There are many other lingua francas centralized on particular regions, such as Arabic, Chinese, French, Greek, Portuguese, Russian and Spanish.
Since all natural languages display a number of irregularities in grammar which makes them more difficult to learn, and they are also associated with the national and cultural dominance of the nation that speaks it as its mother tongue, attention began to focus on the idea of creating an artificial or constructed language as a possible solution. The concept of simplifying an existing language to make it an auxiliary language was already in the Encyclopédie of the 18th century, where Joachim Faiguet de Villeneuve, in the article on Langue, wrote a short proposition of a "laconic" or regularized grammar of French.
Some of the philosophical languages of the 17th–18th centuries could be regarded as proto-auxlangs, as they were intended by their creators to serve as bridges among people of different languages as well as to disambiguate and clarify thought. However, most or all of these languages were, as far as can be told from the surviving publications about them, too incomplete and unfinished to serve as auxlangs (or for any other practical purpose). The first fully developed constructed languages we know of, as well as the first constructed languages devised primarily as auxlangs, originated in the 19th century; Solresol by François Sudre (1787–1862), a language based on musical notes, was the first to gain widespread attention although not, apparently, fluent speakers.
During the 19th century, a bewildering variety of such constructed international auxiliary languages (IALs) were proposed, so Louis Couturat and Léopold Leau in Histoire de la langue universelle (1903) reviewed 38 projects.
Volapük, first described in an article in 1879 by Johann Martin Schleyer and in book form the following year, was the first to garner a widespread international speaker community. Three major Volapük conventions were held, in 1884, 1887, and 1889; the last of them used Volapük as its working language. André Cherpillod writes of the third Volapük convention,
In August 1889 the third convention was held in Paris. About two hundred people from many countries attended. And, unlike in the first two conventions, people spoke only Volapük. For the first time in the history of mankind, sixteen years before the Boulogne convention, an international convention spoke an international language.
However, not long after, the Volapük speaker community broke up due to various factors including controversies between Schleyer and other prominent Volapük speakers, and the appearance of newer, easier-to-learn constructed languages, primarily Esperanto.
Answering the needs of the first successful artificial language community, the Volapükists established the regulatory body of their language, under the name International Volapük Academy (Kadem bevünetik volapüka) at the second Volapük congress in Munich in August 1887. The Academy was set up to conserve and perfect the auxiliary language Volapük, but soon conflicts arose between conservative Volapükists and those who wanted to reform Volapük to make it a more naturalistic language based on the grammar and vocabulary of major world languages. In 1890 Schleyer himself left the original Academy and created a new Volapük Academy with the same name, from people completely loyal to him, which continues to this day.
Under Waldemar Rosenberger, who became the director in 1892, the original Academy began to make considerable changes in the grammar and vocabulary of Volapük. The vocabulary and the grammatical forms unfamiliar to Western Europeans were completely discarded, so that the changes effectively resulted in the creation of a new language, which was named "Idiom Neutral". The name of the Academy was changed to Akademi Internasional de Lingu Universal in 1898 and the circulars of the Academy were written in the new language from that year.
In 1903, the mathematician Giuseppe Peano published his completely new approach to language construction. Inspired by the idea of philosopher Gottfried Wilhelm Leibniz, instead of inventing schematic structures and a priori language, he chose to simplify an existing and once widely used international language, Latin. This simplified Latin, devoid of inflections and declensions, was named Interlingua by Peano but is usually referred to as "Latino sine flexione".
Impressed by Peano's Interlingua, the Akademi Internasional de Lingu Universal effectively chose to abandon Idiom Neutral in favor of Peano's Interlingua in 1908, and it elected Peano as its director. The name of the group then was changed to Academia pro Interlingua (where Interlingua stands for Peano's language). The Academia pro Interlingua survived until about 1939. It was partly Peano's Interlingua that inspired the better-known Interlingua presented in 1951 by the International Auxiliary Language Association (IALA).
After the emergence of Volapük, a wide variety of other auxiliary languages were devised and proposed in the 1880s–1900s, but none except Esperanto gathered a significant speaker community. Esperanto was developed from about 1873–1887 (a first version was ready in 1878), and finally published in 1887, by L. L. Zamenhof, as a primarily schematic language; the word stems are borrowed from Romance, West Germanic and Slavic languages. The key to the relative success of Esperanto was probably the highly productive and elastic system of derivational word formation which allowed speakers to derive hundreds of other words by learning one word root. Moreover, Esperanto is quicker to learn than other languages, usually in a third up to a fifth of the time. From early on, Esperantists created their own culture which helped to form the Esperanto language community.
Within a few years this language had thousands of fluent speakers, primarily in eastern Europe. In 1905 its first world convention was held in Boulogne-sur-Mer. Since then world congresses have been held in different countries every year, except during the two World Wars. Esperanto has become "the most outlandishly successful invented language ever" and the most widely spoken constructed international auxiliary language. Esperanto is probably between the fifty languages which are most used internationally.
In 1922 a proposal by Iran and several other countries in the League of Nations to have Esperanto taught in member nations' schools failed. Esperanto speakers were subject to persecution under Stalin's regime. In Germany under Hitler, in Spain under Franco for about a decade, in Portugal under Salazar, in Romania under Ceaucescu, and in half a dozen Eastern European countries during the late forties and part of the fifties, Esperanto activities and the formation of Esperanto associations were forbidden. In spite of these factors more people continued to learn Esperanto, and significant literary work (both poetry and novels) appeared in Esperanto in the period between the World Wars and after them. Esperanto is spoken today in a growing number of countries and it has multiple generations of native speakers, although it is primarily used as a second language. Of the various constructed language projects, it is Esperanto that has so far come closest to becoming an officially recognized international auxiliary language; China publishes daily news in Esperanto.
The Delegation for the Adoption of an International Auxiliary Language was founded in 1900 by Louis Couturat and others; it tried to get the International Association of Academies to take up the question of an international auxiliary language, study the existing ones and pick one or design a new one. However, the meta-academy declining to do so, the Delegation decided to do the job itself. Among Esperanto speakers there was a general impression that the Delegation would of course choose Esperanto, as it was the only auxlang with a sizable speaker community at the time; it was felt as a betrayal by many Esperanto speakers when in 1907 the Delegation came up with its own reformed version of Esperanto, Ido. Ido drew a significant number of speakers away from Esperanto in the short term, but in the longer term most of these either returned to Esperanto or moved on to other new auxlangs. Besides Ido, a great number of simplified Esperantos, called Esperantidos, emerged as concurrent language projects; still, Ido remains today one of the three most widely spoken auxlangs.
Edgar von Wahl's Occidental (also called "Interlingue") of 1922 was in reaction against the perceived artificiality of some earlier auxlangs, particularly Esperanto. Inspired by Idiom Neutral and Peano's Interlingua, von Wahl created a language whose words, including compound words, would have a high degree of recognizability for those who already know a Romance language. However, this design criterion was in conflict with the ease of coining new compound or derived words on the fly while speaking. Occidental gained a small speaker community in the 1920s and 1930s, and supported several publications, but had almost entirely died out by the 1980s. More recently Occidental has been revived on the Internet.
In 1928 Ido's major intellectual supporter, the Danish linguist Otto Jespersen, abandoned Ido, and published his own planned language, Novial. It was mostly inspired by Idiom Neutral and Occidental, yet it attempted a derivational formalism and schematism sought by Esperanto and Ido. The notability of its creator helped the growth of this auxiliary language, but soon both Novial and Occidental were abandoned in favour of Interlingua, the first auxiliary language based fully on scientific methodology.
The International Auxiliary Language Association (IALA) was founded in 1924 by Alice Vanderbilt Morris; like the earlier Delegation for the Adoption of an International Auxiliary Language, its mission was to study language problems and the existing auxlangs and proposals for auxlangs, and to negotiate some consensus between the supporters of various auxlangs. However, like the Delegation, it finally decided to create its own auxlang. Interlingua, published in 1951, was primarily the work of Alexander Gode, though he built on preliminary work by earlier IALA linguists including André Martinet, and relied on elements from previous naturalistic auxlang projects, like Peano's Interlingua (Latino sine flexione), Jespersen's Novial, von Walh's Occidental (Interlingue), and the Academy's Idiom Neutral. Like Occidental, Interlingua was designed to have words recognizable at sight by those who already know a Romance language or a language like English with much vocabulary borrowed from Romance languages; to attain this end the IALA accepted a degree of grammatical and orthographic complexity considerably greater than in Esperanto or Occidental, though still less than in any natural language.
The theory underlying Interlingua posits an international vocabulary, a large number of words and affixes that are present in a wide range of languages. This already existing international vocabulary was shaped by social forces, science and technology, to "all corners of the world". The goal of the International Auxiliary Language Association was to accept into Interlingua every widely international word in whatever languages it occurred. They conducted studies to identify "the most generally international vocabulary possible", while still maintaining the unity of the language. This scientific approach of generating a language from selected source languages (called control languages) resulted in a vocabulary and grammar that can be called the highest common factor of each major European language.
Interlingua gained a significant speaker community, perhaps roughly the same size as that of Ido (considerably less than the size of Esperanto). Interlingua's success can be explained by the fact that it is the most widely understood international auxiliary language by virtue of its naturalistic (as opposed to schematic) grammar and vocabulary, allowing those familiar with a Romance language, and educated speakers of English, to read and understand it without prior study. Interlingua has some active speakers currently on all continents, and the language is propagated by the Union Mundial pro Interlingua (UMI), and Interlingua is presented on CDs, radio, and television.
After the creation of Interlingua, there were no more successful attempts in international language engineering that would attract a significant number of supporters, thus the enthusiasm about constructed languages gradually decreased in the years between 1960–1990.
All of the auxlangs with a surviving speaker community seem to have benefited from the advent of the Internet, Esperanto more than most. The CONLANG mailing list was founded in 1991; in its early years discussion focused on international auxiliary languages. As people interested in artistic languages and engineered languages grew to be the majority of the list members, and flame-wars between proponents of particular auxlangs irritated these members, a separate AUXLANG mailing list was created in 1997, which has been the primary venue for discussion of auxlangs since then. Besides giving the existing auxlangs with speaker communities a chance to interact rapidly online as well as slowly through postal mail or more rarely in personal meetings, the Internet has also made it easier to publicize new auxlang projects, and a handful of these have gained a small speaker community, including Kotava, Lingua Franca Nova, Lingwa de Planeta, Pandunia, Sambahsa, and Toki Pona.
Not every international auxiliary language is necessarily intended to be used on a global scale. A special subgroup are languages created to facilitate communication between speakers of a certain group of related languages. The oldest known example is a Pan-Slavic language written in 1665 by the Croatian priest Juraj Križanić. He named this language Ruski ("Russian"), but in reality it was a mixture of the Russian ion of Church Slavonic, his own Southern Chakavian dialect of Serbo-Croatian, and, to a lesser degree, Polish.
Most zonal constructed languages were created during the period of romantic nationalism at the end of the 19th century; some were created later. Particularly numerous are the Pan-Slavic languages. However, similar efforts have been made at creating umbrella languages for other language families as well: Tutonish (1902) and Folkspraak (1995) for the Germanic languages, Romanid (1956) for the Romance languages, and Afrihili (1973) for the African continent.
Nowadays, most older zonal constructed languages are known only to specialists. Most notable among modern examples is Interslavic, a project established in 2011 after the merger of several other projects. In 2012 it was reported to have several hundred users.
This section needs expansion. You can help by adding to it. (January 2015)
In the early 1900s auxlangs were already becoming a subject of academic study. Louis Couturat et al. described the controversy in the preface to their book International Language and Science:
Leopold Pfaundler wrote that an IAL was needed for more effective communication among scientists:
For Couturat et al., Volapukists and Esperantists confounded the linguistic aspect of the question with many side issues, and they considered this a main reason why discussion about the idea of an international auxiliary language has appeared unpractical.
Some contemporaries of Couturat, notably Edward Sapir saw the challenge of an auxiliary language not as much as that of identifying a descriptive linguistic answer (of grammar and vocabulary) to global communicative concerns, but rather as one of promoting the notion of a linguistic platform for lasting international understanding. Though interest among scholars, and linguists in particular, waned greatly throughout the 20th century, such differences of approach persist today. Some scholars and interested laymen make concrete language proposals. By contrast, Pei  and others place the broader societal issue first. Yet others argue in favor of a particular language while seeking to establish its social integration.
The vast majority of IALs use the Latin script. Several sounds, e.g. /n/, /m/, /t/, /f/ are written with the same letter as in IPA.
Some consonant sounds found in several Latin-script IAL alphabets are not represented by an ISO 646 letter in IPA. Three have a single letter in IPA, one has a widespread alternative taken from ISO 646:
Four are affricates, each represented in IPA by two letters and a combining marker. They are often written decomposed:
That means that two sounds that are one character in IPA and are not ISO 646, also have no common alternative in ISO 646: ʃ, ʒ.
|ISO 639-3 code||Alphabet name||Non ISO 646 letters||Diacritics||Multigraphs||Sound, which in IPA is described by ISO 646 letter(s), is described by different letter(s)||Sound, which in IPA is described by non-ISO 646 letter(s), is described by different letter(s)|
|lfn||Lingua Franca Nova||No||No||No||Yes (c /k/)||Yes (j /ʒ/, x /ʃ/)|
|rmv||Romanova||No||No||No||Yes (c /k/)||Yes (j /ʃ/)|
|ina||Interlingua||No||No||Yes (qu /kw/ or /k/)||Yes (c /k/)||No|
|ido||Ido||No||No||Yes (ch /tʃ/, qu /kw/, sh /ʃ/)||Yes (c /ts/, q /k/, x /ks/ or /ɡz/)||Yes (j /ʒ/, sh /ʃ/)|
|nov||Novial||No||No||Yes (ch /tʃ/, sh /ʃ/, y /j/)||Yes (q /k/, x /ks/)||Yes (j /ʒ/, sh /ʃ/)|
|igs||Interglossa||No||No||Yes (ph, th, ch, rh -> /f/, /t/, /k/, /r/)||Yes (c /k/, q /k/, x /ks/, z /ts/)||No|
|epo||Esperanto||No||Yes (ĉ, ĝ, ĥ, ĵ, ŝ, ŭ)||No||Yes (c /ts/)||No|
|-||Mundolinco||No||No||No||Yes (c /k/)||No|
|-||Glosa||No||No||Yes (sc /ʃ/)||Yes (q /kw/, x /ks/)||Yes (c /tʃ/, sc /ʃ/)|
|-||Sambahsa||No||No||Yes (ch /tʃ/, sh /ʃ/, and more)||Yes (y, as a semi-vowel /j/, x /ks, gz/ and more)||Yes (j /ʒ/, ch /tʃ/, sh /ʃ/, sh /ç/ and more)|
|-||Idiom Neutral||No||No||Yes (sh /ʃ/)||Yes (y /j/)||Yes (c /tʃ/, j /ʒ/, sh /ʃ/)|
|-||Lingwa de planeta||No||No||Yes (ch /tʃ/, sh /ʃ/)||Yes (x /gs/, z /dz/)||Yes (c in ch /tʃ/, j /dʒ/)|
|-||Interslavic||No||Yes (č, ě, š, ž)||dž, but similar to or same as d+ž||Yes (c /ts/, y /i ~ ɪ/)||Yes (č /tʃ/, š /ʃ/, ž /ʒ/)|
|-||Uropi||Yes (ʒ /ʒ/)||No||No||No||Yes (c /ʃ/)|
|-||Novbasa||No||No||Yes (c /tʃ/, x /ʃ/)||Yes (x /ʃ/)||No|
The following classification of auxiliary languages was developed by Pierre Janton in 1993:
Some examples of the best known international auxiliary languages are shown below for comparative purposes. As a reference for comparison, you can find the English and Latin versions of the Lord's Prayer (a text which is regularly used for linguistic comparisons) here:
|The Lord's Prayer in English (KJV)||The Lord's Prayer in Latin|
Our Father, who art in heaven,
Pater noster, qui es in cælis,
|Volapük version||Esperanto version||Ido version||Idiom Neutral version|
O Fat obas, kel binol in süls,
Patro Nia, kiu estas en la ĉielo,
Patro nia, qua esas en la cielo,
Nostr patr kel es in sieli!
|Latino sine flexione version||Occidental version||Novial version||Interlingua de IALA version|
Patre nostro, qui es in celos,
Patre nor, qui es in li cieles,
Nusen Patre, kel es in siele,
Patre nostre, qui es in le celos,
|Lingua Franca Nova version||Glosa version||Kotava version||toki pona version|
Nosa Padre, ci es en la sielo,
Na patri in urani:
Minaf Gadik dan koe kelt til,
mama pi mi mute o, sina lon sewi kon.
As has been pointed out, the issue of an international language is not so much which, but how. Several approaches exist toward the eventual full expansion and consolidation of an international auxiliary language.
There have been a number of proposals for using pictures, ideograms, diagrams, and other pictorial representations for international communications. Examples range from the original Characteristica Universalis proposed by the philosopher Leibniz, to suggestions for the adoption of Chinese writing, to recent inventions such as Blissymbol.
Within the scientific community, there is already considerable agreement in the form of the schematics used to represent electronic circuits, chemical symbols, mathematical symbols, and the Energy Systems Language of systems ecology. We can also see the international efforts at regularizing symbols used to regulate traffic, to indicate resources for tourists, and in maps. Some symbols have become nearly universal through their consistent use in computers and on the internet.
An international auxiliary sign language has been developed by deaf people who meet regularly at international forums such as sporting events or in political organisations. Previously referred to as Gestuno but now more commonly known simply as 'international sign', the language has continued to develop since the first signs were standardised in 1973, and it is now in widespread use. International sign is distinct in many ways from spoken IALs; many signs are iconic and signers tend to insert these signs into the grammar of their own sign language, with an emphasis on visually intuitive gestures and mime. A simple sign language called Plains Indian Sign Language was used by indigenous peoples of the Americas.
Gestuno is not to be confused with the separate and unrelated sign language Signuno, which is essentially a Signed Exact Esperanto. Signuno is not in any significant use, and is based on the Esperanto community rather than based on the international Deaf community.
There has been considerable criticism of international auxiliary languages, both in terms of individual proposals, types of proposals, and in more general terms.
Criticisms directed against Esperanto and other early auxiliary languages in the late 19th century included the idea that different races have sufficiently different speech organs that an international language might work locally in Europe, but hardly worldwide, and the prediction that if adopted, such an auxlang would rapidly break up into local dialects. Advances in linguistics have done away with the first of these, and the limited but significant use of Esperanto, Ido and Interlingua on an international scale, without breakup into unintelligible dialects, has shown that either a rapid break-up into dialects shall not happen too soon in the future, or that there is enough constant 'standardisation' to reduce the diversity of the language. Subsequently, much criticism has been focused either on the artificiality of these auxlangs, or on the argumentativeness of auxlang proponents and their failure to agree on one auxlang, or even on objective criteria by which to judge auxlangs. However, probably the most common criticism is that a constructed auxlang is unnecessary because natural languages such as English are already in wide use as auxlangs and work well enough for that purpose.
One criticism already prevalent in the late 19th century, and still sometimes heard today, is that an international language might hasten the extinction of minority languages. One response has been that, even if this happens, the benefits would outweigh the costs;. Another response has been that proponents of auxlangs, particularly in the Esperanto movement, are often thought to also be proponents of measures to conserve and promote minority languages[why?] and cultures. Based on Baha'i writ, Meyjes (2006) sees an International Auxiliary Language intended to be implemented in ways that shield native tongues from undue pressures from any traditional lingua franca, while enabling inter-community communication worldwide 
Although referred to as international languages, most of these languages have historically been constructed on the basis of Western European languages. In the late 19th and early 20th centuries it was common for Volapük and Esperanto, and to some extent Ido, to be criticized for not being Western European enough; Occidental and Interlingua were (among other things) responses to this kind of criticism. More recently all these major auxlangs have been criticized for being too European and not global enough. One response to this criticism has been that doing otherwise in no way makes the language easier for anyone, while drawing away from the sources of much international vocabulary, technical and popular. Another response, primarily from Esperanto speakers, is that the internationality of a language has more to do with the culture of its speakers than with its linguistic properties. Esperanto itself uses individual words from Indo-European languages, but its grammar is much more similar to Chinese and Greek, (while being flexible enough in grammar and sentence structure to be able to copy the word-order of Japanese, Indonesian and English all about as well as each other) so it's difficult to judge how much of an Indo-European language it even is. The term "Euroclone" was coined to refer to these languages in contrast to "worldlangs" with global vocabulary sources; the term is sometimes applied only to self-proclaimed "naturalistic" auxlangs such as Occidental and Interlingua, sometimes to all auxlangs with primarily European vocabulary sources, regardless of their grammar, including Esperanto and Lingua Franca Nova.
The response to this argument was made by Alexander Gode and reiterated by Mario Pei: A vocabulary selected from a broad variety of languages does not make the language any easier for speakers of any one language. Gode's example compares a paragraph in Interlingua with a paragraph with words from Chinese, Japanese, Malay, and other non-European languages. The first, he argues, should be understood by those familiar with the Romance languages, and not overly difficult for most English speakers:
The second, in contrast, should not only be difficult for speakers of European languages, but Malay speakers likely will not understand the Chinese words, Chinese speakers will likely not understand the Japanese words, and Japanese speakers likely will not understand the Malay words:
Gode argues, additionally, that the western languages are the unofficial languages of international science, medicine, and technology, and therefore an IAL based on them provides the best access to that literature. Nevertheless, it must be said that a more neutral vocabulary, perhaps even an a priori one, would be less offensive to some non-Europeans.
In the 1990s and early 2000s, many proposals for auxlangs based on global sources of vocabulary and grammar have been made, but most (like the majority of the European-based auxlangs of earlier decades) remain sketches too incomplete to be speakable, and of the more complete ones, few have gained any speakers. More recently there has been a trend, on the AUXLANG mailing list and on the more recently founded worldlang mailing list, to greater collaboration between various proponents of a more globally based auxlang.
See List of constructed languages#Auxiliary languages for a list of designed international auxiliary languages.
But in terms of invented languages, it’s the most outlandishly successful invented language ever. It has thousands of speakers—even native speakers—and that’s a major accomplishment as compared to the 900 or so other languages that have no speakers. – Arika Okrent