Most auxiliary languages I know of, especially Esperanto, are primarily a posteriori—that is, their vocabulary or grammar are derived from other existing languages, and most are fairly Eurocentric. While many might have a priori grammar, but not vocabulary, I have yet to see another language that is entirely a priori—not derived from other languages. Do any such languages exist? Note I am talking about languages designed to be an international auxiliary language.

  • I would say this is very hard, as we all speak language(s), and that limits our imagination somewhat. If you come up with a new language, you are bound to fall back on what you know already. Otherwise you might end up with a language which is unlike any other, but doesn't actually work as a language. Commented Jan 25, 2019 at 12:45
  • 1
    @OliverMason By that definition every conlang would be a posteriori, except for things like Europan. But that is not how those words are usually used. For example, my own main conlang has a lot of derivational morphology (inspired by Greenlandic), verbs have inherent lexical aspects affecting affixes (inspired by PIE) and the syntax features an absolutive pivot (inspired by Dyirbal). But both the lexicon and the complete grammar is entirely self-made with no relation to existing languages. Everyone has inspirations, that doesn’t make it a posteriori. Commented Jan 26, 2019 at 11:56

3 Answers 3


Short answer: I've never seen or read a description of what you're seeking.

Long answer: What you're seeking is a most unlikely beast, reason being...

Generally speaking, auxiliary languages seek being completely or nearly completely a posteriori for reasons of simple expedience. Common design goals of an auxiliary language are ease of learning and simplicity of use. These goals are best met when vocabulary and grammar are familiar to the target audience. This is why Interlingua and Esperanto are considered "easy" languages to learn and have gained considerable user communities, with Esperanto boasting a small community of native level speakers.

What you're describing, a completely a priori invented language is most usually the domain of the artistic language, the engineered language and the philosophical language. With the exception of the philosophical inventors, most glossopoets are not interested in propagandising their languages as auxiliary languages. Occasionally a philosophical language inventor will propose his language as a means of general communication, but this is usually done from a position of ignorance as to how language works (accomplished auxiliary language proponents are usually quite well aware how language works in the wild!).

Auxiliary languages tend not to be classified as a priori simply because they impose layers of difficulty that run contrary to the usual design parameters of the genre. However, it can potentially be argued that a priori invented languages can become auxiliary languages after a fashion and if the appropriate stars align. For example, it may be that Klingon has seen some use as an ad hoc auxiliary language if, for example, two groups of Star Trek fans who do not share a language in common other than Klingon happen to meet at a SciFi convention.

Needless to say, even if there were an actual auxiliary language that is classified as purely a priori, it certainly isn't famous. Otherwise, we'd know about it!


There are various "a priori" constructed languages, though they are not as successful as "a posteriori" languages have been.

They include:

  1. Spokil
  2. Ro
  3. Kotava
  4. Solresol
  5. Babm
  6. Blisssymbols (Written, ideographic language only)
  7. Nal Bino (modification of Volapuk)
  8. Sona

We will have to go back some centuries in time to find a language like this. Since the success of Esperanto (and, to a lesser degree Interlingua, Glosa, and Toki Pona) it seems to be clear that an auxiliary language has to be naturalistic in some way to catch on. Nowadays, a priory languages (e.g., Loglan and its forks) are only designed with other purposes.

With this in mind, probably Solresol (1817) is the most famous a priory auxiliary language.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.