An international auxiliary language (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 native language. A language is a dynamic set of visual auditory or tactile Symbols of Communication and the elements used to manipulate them A first language (also mother tongue, native language, arterial language, or L1) is the language a human being learns from birth An auxiliary language is primarily a second language.
Languages of dominant societies over the centuries have served as auxiliary languages, sometimes approaching the international level. French and English have been used as such in recent times in many parts of the world. French ( français,) is a Romance language spoken around the world by 118 million people as a native language and by about 180 to 260 million people English is a West Germanic language originating in England and is the First language for most people in the United Kingdom, the United States  However, as these languages are associated with the very dominance - cultural, political, and economic - that made them popular, they are often met with strong resistance as well. For this reason, many have turned to the idea of promoting an artificial or constructed language as a possible solution. A constructed or artificial language known colloquially or informally as a conlang is a Language whose Phonology, Grammar 
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 phrase is used to refer to planned or constructed languages proposed specifically to ease worldwide international communication, such as Esperanto, Ido, and Interlingua. A constructed or artificial language known colloquially or informally as a conlang is a Language whose Phonology, Grammar is by far the most widely spoken constructed International auxiliary language in the world Ido (ˈiːdoʊ is a Constructed language created with the goal of becoming a universal second language for speakers of different linguistic backgrounds as a language easier Interlingua is an International auxiliary language (IAL developed between 1937 and 1951 by the International Auxiliary Language Association (IALA 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. International English is the concept of the English language as a global means of communication in numerous dialects and also the movement towards an international standard A universal language is a hypothetical historical or mythical language said to be spoken and understood by all or most of the world's populationor in some circles is said to be understood Some auxiliary language aficionados call these languages auxlangs.
The history of auxiliary language is controversial. Louis Couturat et al. Louis Couturat ( January 17, 1868 - August 3, 1914) was a French Logician mathematician, philosopher  exemplified the controversy in the Preface to their book on International Language and Science:
The question of a so-called world-language, or better expressed, an international auxiliary language, was during the now past Volapük period, and is still in the present Esperanto movement, so much in the hands of Utopians, fanatics and enthusiasts, that it is difficult to form an unbiased opinion concerning it, although a good idea lies at its basis. Volapük (volaˈpyk or ˈvɒləpʊk in English is a Constructed language, created in 1879-1880 by Johann Martin Schleyer, a Roman Catholic priest is by far the most widely spoken constructed International auxiliary language in the world (1910, p. v).
For Couturat et al, both Volapukists and Esperantists confounded the linguistic aspect of the question with many side issues, and for this reason discussions about the international auxiliary language has appeared unpractical. However as Pfaundler wrote in the same publication, the language was intimately connected to science, and not simply linguistics:
All who are occupied with the reading or writing of scientific literature have assuredly very often felt the want of a common scientific language, and regretted the great loss of time and trouble caused by the multiplicity of languages employed in scientific literature.
The history of the most notable constructed auxiliary languages can be summarized in table form:
|Language name||ISO||Year of first|
|Solresol||1827||François Sudre||The famous "musical language"|
|Communicationssprache||1839||Joseph Schipfer||Based on French vocabulary|
|Universalglot||1868||Jean Pirro||Arguably the first fully developed IAL|
|Volapük||vo, vol||1879–1880||Johann Martin Schleyer||First to generate international interest in IALs|
|Esperanto||eo, epo||1887||L. L. Zamenhof||By far the most popular constructed language. Solresol is an Artificial language devised by François Sudre, beginning in 1827 Jean-François Sudre was a French Author and Musician born in Albi France in 1787 and died in Paris in 1862 Communicationssprache is a very early example of a proposed International auxiliary language, published in 1839 in Wiesbaden by Joseph Schipfer (1761-1843 Universalglot is an a posteriori International auxiliary language published by the French linguist Jean Pirro in 1868 in Tentative Jean Pirro (1831-1886 was a French linguist who in 1868 invented the "universal language" Universalglot. Volapük (volaˈpyk or ˈvɒləpʊk in English is a Constructed language, created in 1879-1880 by Johann Martin Schleyer, a Roman Catholic priest Johann Martin Schleyer ( July 18, 1831 &ndash August 16, 1912) German Catholic priest who invented the Constructed is by far the most widely spoken constructed International auxiliary language in the world Ludwig Lazarus Zamenhof (ˈzɑːmɨnhɒf in English born Eliezer Samenhof December 15 1859 &ndash April 14 1917 was an ophthalmologist, Philologist|
|Spokil||1887 or 1890||Adolph Nicolas||An a priori language by a former Volapük advocate|
|Mundolinco||1888||J. Spokil is a Constructed language, created by the Frenchman Adolphe Nicolas. Mundolinco is a Constructed language created by the Dutch author J Braakman||The first esperantido|
|Idiom Neutral||1902||Waldemar Rosenberger||A naturalistic IAL by a former advocate of Volapük|
|Latino sine Flexione||1903||Giuseppe Peano||"Latin without inflections," it replaced Idiom Neutral in 1908|
|Ido||io, ido||1907||Delegation for the Adoption of an International Auxiliary Language||The most successful offspring of Esperanto|
|Adjuvilo||1908||Claudius Colas||An esperantido created to cause dissent among Idoists|
|Occidental (aka Interlingue)||ie, ile||1922||Edgar de Wahl||A sophisticated naturalistic IAL|
|Novial||nov||1928||Otto Jespersen||Another sophisticated naturalistic IAL|
|Sona||1935||Kenneth Searight||Best known attempt at an unbiased vocabulary|
|Esperanto II||1937||René de Saussure||Last of the esperantidos|
|Mondial||1940s||Helge Heimer||A naturalistic European language|
|Glosa||igs||1943||Lancelot Hogben, et al. Esperantido is the term used within the Esperanto and Constructed language communities to describe a language project based on or inspired by Esperanto Idiom Neutral is an International auxiliary language, published in 1902 by the International Academy of the Universal Language ( Akademi Internasional de Waldemar Rosenberger, from Saint Petersburg, Russia, was a director of the Volapük Academy Latino sine flexione ( Latin without Inflections is an Auxiliary language invented by the Italian mathematician Giuseppe Peano (1858 - 1932 Giuseppe Peano ( August 27, 1858 &ndash April 20, 1932) was an Italian Mathematician, whose work was of exceptional Ido (ˈiːdoʊ is a Constructed language created with the goal of becoming a universal second language for speakers of different linguistic backgrounds as a language easier The Delegation for the Adoption of an International Auxiliary Language (French Délégation pour l'Adoption d'une Langue Auxiliaire Internationale) was a body of academics convened Adjuvilo is a Language created in 1908 by Claudius Colas under the Pseudonym of "Profesoro V Claudius Colas (also known by the pseudonym Profesoro V Esperema) was a French Esperantist who lived from 1884 to 1914 The Language Occidental, later Interlingue, is a planned language created by the Balto-German naval officer and teacher Edgar de Wahl Edgar von Wahl or Edgar de Wahl (born August 11, 1867 in Olwiopol Imperial Russia (now Pervomaysk, Ukraine) died in Novial ("new" + ''IAL International Auxiliary Language'' is a constructed International auxiliary language (IAL intended to facilitate international Jens Otto Harry Jespersen or Otto Jespersen ʌtˢo ˈjɛsb̥ɐsn̩ ( July 16, 1860 - April 30, 1943) was a Danish linguist Sona is an International auxiliary language created by Kenneth Searight and described in a book he published in 1935. Kenneth Searight (born Arthur Kenneth Searight) (December 1883 - 1957 was the creator of the International auxiliary language Sona. Esperanto II was a reform of Esperanto proposed by René de Saussure in 1937 the last of a long series of such proposals beginning with a 1907 response to Ido René de Saussure ( March 17, 1868, Geneva &ndash December 2, 1943, Berne) was a Swiss Esperantist Esperantido is the term used within the Esperanto and Constructed language communities to describe a language project based on or inspired by Esperanto Mondial is an International auxiliary language created by Dr Helge Heimer a Swede in the 1940s Glosa is an isolating International auxiliary language (sometimes called an auxlang or an "IAL" Lancelot Thomas Hogben ( 9 December[[ 895]] - 22 August 1975) was a versatile British experimental Zoologist, and medical Statistician||Originally called Interglossa, Glosa has a strong Greco-Latin vocabulary|
|Interlingua||ia, ina||1951||International Auxiliary Language Association||A large project to discover common European vocabulary|
|Frater||1957||Pham Xuan Thai||Innovative blend of Greco-Latin roots and non-western grammar|
|Kotava||avk||1978||Staren Fetcey||A sophisticated a priori IAL|
|Lingua Franca Nova||lfn||1998||C. George Boeree et al. Interlingua is an International auxiliary language (IAL developed between 1937 and 1951 by the International Auxiliary Language Association (IALA The International Auxiliary Language Association (IALA was founded in 1924 to " promote widespread study discussion and publicity of all questions involved in the establishment Frater ( Lingua sistemfrater), an a posteriori International auxiliary language, published in Frater (Lingua sistemfrater Kotava is a proposed International auxiliary language (IAL that focuses especially on the principle of cultural neutrality Lingua Franca Nova (abbreviated LFN) is an auxiliary Constructed language created by Dr Dr C George Boeree (born January 15, 1952 in the Netherlands) is a professor of Psychology at Shippensburg University of Pennsylvania||A Romance vocabulary with a creole-like grammar|
The following classification of auxiliary languages was developed by Pierre Janton in 1993: 
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. An ideogram or ideograph (from Greek idea "idea" + grafo "to write" is a Graphic symbol that represents an Idea 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. Written Chinese comprises the written symbols used to represent Spoken Chinese and the rules about how they are arranged and punctuated Blissymbols or Blissymbolics were conceived of as an Ideographic Writing system consisting of several hundred basic Symbols each representing 
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. A schematic is a diagram that represents the elements of a System using abstract graphic Symbols rather than realistic pictures A circuit diagram (also known as an electrical diagram Wiring diagram, elementary diagram or electronic Schematic) is a simplified conventional pictorial representation See also Chemical formula. A chemical symbol is an Abbreviation or shortened version of the name of a Chemical element This is a listing of common symbols found within all branches of the science of Mathematics. The Energy Systems Language (right also referred to as Energese, Energy Circuit Language and Generic Systems Symbols, was developed by the Ecologist Systems ecology is an Interdisciplinary field of Ecology, taking a holistic approach to the study of ecological systems especially Ecosystems 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 (also Gestuno, International Sign Language (ISL International Sign Pidgin and International Gesture (IG is an International Sign (IS (also Gestuno, International Sign Language (ISL International Sign Pidgin and International Gesture (IG is an 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. In functional- Cognitive linguistics, as well as in Semiotics, iconicity is the conceived Similarity or Analogy between a form of a Sign A simple sign language called Plains Indian Sign Language was used by indigenous peoples of the Americas. Plains Indian Sign Language (PISL is a Sign language formerly used as an auxiliary Interlanguage between Native Americans of the Great Plains For indigenous peoples in the United States other than Hawaii and Alaska see also Native Americans in the United States.
Gestuno is not to be confused with the separate and unrelated sign language Signuno, which is essentially a Signed Exact Esperanto. International Sign (IS (also Gestuno, International Sign Language (ISL International Sign Pidgin and International Gesture (IG is an Signuno, or Signed Exact Esperanto, is a manual encoding of Esperanto proposed by an anonymous author with Gestuno roots modified for Esperanto morphology 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 and in more general terms. 
Although referred to as International languages, most of these languages are constructed on the basis of Western European languages. Western Europe at its most general meaning means 'all the countries in the West of Europe ' The 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. 
See List of constructed languages for a list of constructed international auxiliary languages. This list of Constructed languages is in alphabetical order and divided into auxiliary, engineered, and artistic (including fictional Languages