A constructed or artificial language—also colloquially known as a conlang—is a language whose grammar (possibly including its phonological system and/or vocabulary) have been devised by an individual or group, instead of having naturally evolved. Among the many possible reasons to create a constructed language are the will to ease human communication (see international auxiliary language and code); to make a fictional story or a constructed world more veracious; linguistic experimentation or simply for aesthetic pleasure.
Humans have also deliberately constructed artificial languages such as Esperanto, Loglan, Lojban, Ido, Interlingua, Klingon, and Volapük. Esperanto was created by L. L. Zamenhof as a compilation of various elements of different languages, and was intended to be a lingua franca facilitating international communication.
There are two main categories into which a constructed language can be classified:
- A priori language: The grammar and vocabulary is created from scratch using the author(s) imagination or, less usually, by taking strings randomly generated by a computer. Example: Klingon.
- A posteriori language: Its grammar and/or vocabulary are based on some existing language, either as a variation of one or as a mixture of various. Example: Esperanto.