# Interlingue
**Interlingue**, originally published as **Occidental**, is a naturalistic (designed to imitate existing natural languages) international auxiliary language created by the [Baltic German](https://www.edgepedia.org/baltic-german) teacher Edgar von Wahl (or de Wahl, 1867–1948) and first published in 1922. It was designed to look and work like the existing European languages, especially the Romance ones, so that it could be understood at first sight without previous instruction, and it was renamed Interlingue in 1949 without any change to the language itself.[1](https://interlingue.narod.ru/eng.html) • [2](https://interlingue.pbworks.com/w/page/4887780/Grammatica%20de%20Interlingue%20%28English%29)
| Key fact | Detail |
|---|---|
| Creator | Edgar von Wahl (de Wahl), a teacher from Tallinn, born 11 August 1867 in Olwiopol (Ukraine), died 1948[3](https://interlingue.pbworks.com/w/page/5627796/Occidental%201922%20by%20Edgar%20de%20Wahl%20%28EN%29) • [4](https://www.keeljakirjandus.ee/en/archives/38339) |
| First publication | 1922, in de Wahl's paper *Kosmoglott*, later named *Cosmoglotta*[1](https://interlingue.narod.ru/eng.html) |
| Renaming | The name Occidental was changed to Interlingue in 1949, without changing the language, to avoid the political aspect of the name "Occidental-Union"[2](https://interlingue.pbworks.com/w/page/4887780/Grammatica%20de%20Interlingue%20%28English%29) |
| Design goal | Comprehensible at first sight to Europeans, with the aspect of an almost natural language, easy to read and easy in grammatical structure[1](https://interlingue.narod.ru/eng.html) |
| Word formation | De Wahl's three rules derive stems from infinitives, with six named exceptions (ceder, seder, mover, tener, verter, venir)[1](https://interlingue.narod.ru/eng.html) |
| Recognition | IALA classified it as one of the systems of demonstrated usefulness; a bibliometric survey records 99 journals in or about the language, 0.87% of the recorded corpus[1](https://interlingue.narod.ru/eng.html) • [5](https://www.indecs.eu/2015/indecs2015-pp200-215.pdf) |
| Digital presence | Interlingue is among the IAL editions analyzed on Wikipedia, where the IAL editions together hold 1.3 million articles and 15.6 million monthly views[6](https://arxiv.org/abs/2408.15873) |
## Origins
[Edgar de Wahl](https://www.edgepedia.org/edgar-de-wahl) came to language construction through the earlier projects. He studied Volapük in 1887, took up [Esperanto](https://www.edgepedia.org/esperanto) a year later, gave both up, and began independent studies in 1894. From 1906 to 1907 he collaborated with [Rosenberger](https://www.edgepedia.org/rosenberger), then president of the Kadem bevünetik volapüka, later the Akademi Internasional de lingu universal. In 1907 he submitted a memorandum to the Délégation pour l'adoption d'une langue auxiliaire internationale on the construction of an auxiliary language, without submitting a complete language. The memorandum's principal ideas were that none of the existing systems was satisfactory, that the international language should be founded on international linguistic material, that really international words should be obtained through a number of formulated rules, that its grammar should produce no forms deviating from the ethnic languages, and that it should possess an international orthography.[1](https://interlingue.narod.ru/eng.html)
These ideas were not accepted by the [Delegation](https://www.edgepedia.org/delegation), and de Wahl elaborated his own system until in 1922 he published it as Occidental in his paper *Kosmoglott*, later named *Cosmoglotta*. The name indicated his principal idea: a language for the Occidental world, based chiefly on the [Romance languages](https://www.edgepedia.org/romance-languages), with word formation built on the suffixes actually used in the existing modern languages.[1](https://interlingue.narod.ru/eng.html) • [7](https://interlanguages.net/AILocc.html)
In 1935, while talking with Otto Jespersen, de Wahl reaffirmed his principles: a constructed language ought to be an organic, self-governing whole, developing under its own rules and fitting in new elements harmoniously while observing the general laws that govern natural ethnic languages, and it ought to draw on the international forms shared by European languages in pronunciation, orthography, and style of expression. Occidental's theories influenced Jespersen and his Novial to some extent, and IALA (the International Auxiliary Language Association) classified Occidental as one of the systems of demonstrated usefulness.[1](https://interlingue.narod.ru/eng.html)
**Historical assessment.** Triin Tark, PhD, a researcher writing in the Estonian journal *[Keel ja Kirjandus](https://www.edgepedia.org/keel-ja-kirjandus)*, describes Occidental as one of the most successful planned languages of the first half of the 20th century and attributes the outcome both to the remarkable popularity of the auxiliary language idea, promoted by organizations such as the [Delegation for the Adoption of an International Auxiliary Language](https://www.edgepedia.org/delegation-for-the-adoption-of-an-international-auxiliary-language), the [League of Nations](https://www.edgepedia.org/league-of-nations), and the International Auxiliary Language Association, and to de Wahl's own decades of experience in the constructed-language community and his strategies of promotion in the 1920s.[4](https://www.keeljakirjandus.ee/en/archives/38339)
## Grammar
The alphabet has 26 letters, with y functioning as both consonant and vowel. Stress falls on the vowel before the last consonant; the plural ending -(e)s and the adverbial endings -bil, -ic, -im, -ul, and -um remain unstressed, and words that break these rules are marked with an accent.[1](https://interlingue.narod.ru/eng.html)
**Articles and nouns.** The definite article is *li* for all genders and numbers, and the indefinite article is *un*; *lu* may serve as an article when an adjective stands alone as an abstract conception. The singular noun takes no specific grammatical ending. The plural is formed with -s after vowels and after -c, -g, -um, and with -es after other consonants.[1](https://interlingue.narod.ru/eng.html)
**Verbs.** The infinitive ends in -r (*amar*), and the present indicative is the stem alone (*yo ama*, *tu ama*, *il ama*). The past tense adds -t to the present (*yo amat*), the future uses the auxiliary *va* (*yo va ear*, I shall go), and the conditional uses *vell* (*illa vell ear*, she would go). The perfect and pluperfect place the auxiliary before the past participle (*yo ha amat*, I have loved), and the passive is formed with *esser* (*yo es videt*, I am seen). The conjugation of *esser* is regular across persons, with present *es*, past *esset*, and future *va esser*.[1](https://interlingue.narod.ru/eng.html)
**Word formation.** Occidental accepts both direct and indirect derivation, and direct derivation follows the three rules of de Wahl, applied to the stem obtained by removing the infinitive -r or -e/r:
1. If the stem ends in a vowel, add -t or change -y into -t (*crear*, *creat*, *creator*).
2. If the final consonant of the stem is d or r, it changes into -s (*decider*, *decis*, *decision*).
3. In all other cases, removal of the infinitive -r gives the required perfect stem (*ducer*, *duct-*, *duction*).
Six exceptions are listed: *ceder* with perfect stem *cess-*, *seder* with *sess-*, *mover* with *mot-*, *tener* with *tent-*, *verter* with *vers-*, and *venir* with *vent-*.[1](https://interlingue.narod.ru/eng.html) The grammar page of the Interlingue Union describes this grammar as complete in the sense that it contains all essential rules used in the texts of *Cosmoglotta*, the official organ of the Interlingue Union, and in the *Complet Curse de Interlingue* (Complete Course of Interlingue).[2](https://interlingue.pbworks.com/w/page/4887780/Grammatica%20de%20Interlingue%20%28English%29)
**Syntax.** The ordinary word order is subject-verb-object. Short adjectives generally precede the noun (*un bon idé*), while long adjectives may follow it (*li lingue international*). Interrogatives begin with *esque* or an interrogative pronoun or adverb (*qui*, *quo*, *quande*), inversion without *esque* is permitted (*have vu li libre?*), and negation is marked with *ne* (*il ne ha fat it*).[1](https://interlingue.narod.ru/eng.html)
## Reception and classification
Within the field of [interlinguistics](https://www.edgepedia.org/interlinguistics), the study of planned languages, Occidental-Interlingue stands in the naturalistic tradition. [Planned languages](https://www.edgepedia.org/constructed-language) are languages consciously created according to given criteria principally to facilitate international communication, as defined by the interlinguist Detlev Blanke, whose scholarly surveys of the field are standard references.[8](https://dvd.ikso.net/faka/esperanto/Blanke/Interlingvistiko_Blanke_en.pdf) Occidental appears in Henry Jacob's 1947 comparative study *A Planned Auxiliary Language*, which gives full grammatical detail for five systems of demonstrated usefulness: Esperanto, Ido, Occidental, Novial, and Latino sine flexione.[9](https://www.interlanguages.net/PAL.html) IALA's 1936 committee likewise admitted Occidental among the candidate languages it called existing, constructed languages of demonstrated usefulness, requiring that a candidate be well developed with vocabulary, grammar, and word formation, and in actual use in speech and writing.[10](https://interlanguages.net/PALiala.html)
Not every philosopher of language approved of the design. The philosopher and logician [Rudolf Carnap](https://www.edgepedia.org/rudolf-carnap), who in 1929 declined [Giuseppe Peano](https://www.edgepedia.org/giuseppe-peano)'s invitation to join his Academia pro [Interlingua](https://www.edgepedia.org/interlingua) because Peano's language form seemed too archaic and too difficult for non-Europeans, rejected de Wahl's Occidental without detailed study because the sacrifice with respect to logical structure and regularity appeared unacceptable to him.[11](https://link.springer.com/chapter/10.1007/978-3-662-72937-3_9)
A bibliometric survey of periodicals in interlinguistics counted, for the language with founding year 1922 (Occidental-Interlingue), 99 journals in or about the language, 0.87% of the total corpus, against 10,440 journals (91.63%) for Esperanto, 297 for Volapük, 286 for Ido, and 83 for Interlingua (IALA/Gode).[5](https://www.indecs.eu/2015/indecs2015-pp200-215.pdf)
## Digital-era presence
Interlingue survives as one of the constructed languages with an online community and its own [Wikipedia](https://www.edgepedia.org/wikipedia) edition. A 2024 study by Marta Alet and Diego Saez-Trumper analyzed the Wikipedia editions of the international auxiliary languages Simple English, Esperanto, Ido, Interlingua, Volapük, Interlingue, and Novial against English, Spanish, and Catalan, finding 1.3 million articles in the IAL editions gathering 15.6 million monthly views and concluding that IAL editions behave proportionally to their communities' size, so growth depends on augmenting the amount and quality of content offered.[6](https://arxiv.org/abs/2408.15873)
## References
1. [H. Jacob on Occidental (1947): Occidental (1922) by Edgar de Wahl](https://interlingue.narod.ru/eng.html)
2. [Interlingue Occidental / Grammatica de Interlingue (English)](https://interlingue.pbworks.com/w/page/4887780/Grammatica%20de%20Interlingue%20%28English%29)
3. [Interlingue Occidental / Occidental 1922 by Edgar de Wahl (EN)](https://interlingue.pbworks.com/w/page/5627796/Occidental%201922%20by%20Edgar%20de%20Wahl%20%28EN%29)
4. [Triin Tark, "In the laboratory of utopian world reform: The Tallinn teacher Edgar von Wahl and the international auxiliary language movement," Keel ja Kirjandus](https://www.keeljakirjandus.ee/en/archives/38339)
5. [Interdisciplinary Description of Complex Systems 13(2), 200-215, 2015](https://www.indecs.eu/2015/indecs2015-pp200-215.pdf)
6. [Marta Alet, Diego Saez-Trumper (2024). Constructing a Common Ground: Analyzing the quality and usage of International Auxiliary Languages in Wikipedia. arXiv:2408.15873.](https://arxiv.org/abs/2408.15873)
7. [AIL - Occidental, interlanguages.net](https://interlanguages.net/AILocc.html)
8. [Detlev Blanke, Interlinguistics and Esperanto studies: Paths to the scholarly literature (Esperanto Documents 47A, 2004)](https://dvd.ikso.net/faka/esperanto/Blanke/Interlingvistiko_Blanke_en.pdf)
9. [Henry Jacob, A Planned Auxiliary Language (1947), interlanguages.net](https://www.interlanguages.net/PAL.html)
10. [A Planned Auxiliary Language: The Work of the IALA, interlanguages.net](https://interlanguages.net/PALiala.html)
11. [Planned Languages: Esperanto and Basic English, Springer Nature](https://link.springer.com/chapter/10.1007/978-3-662-72937-3_9)
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*Topic: Encyclopedia › Society and history › Languages and linguistics › Languages and dialects › Named languages by region › Named languages overview*
*Initially written Sep 17, 2026 · Reviewed: Oct 25, 2026 · Edited: Oct 15, 2026; Oct 25, 2026 · Last review: Oct 25, 2026*
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License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license