An artificial or constructed language, colloquially conlang, is a language whose vocabulary and grammar were specifically devised by humans, rather than having naturally evolved as part of a culture like a natural language. Some are designed for use in human communication, the same as natural languages, usually to function as an international auxiliary language, but others are created for use in fiction, linguistic experimentation, secrecy (codes), or simply for the sake of it. Conlangers differ on whether linguistic creation of the last kind is to be considered an art or a hobby.
The term planned language is also used, when referring to international auxiliary languages, and by those who may object to the more common term "artificial". Speakers of Esperanto, for example, have said that "Esperanto is an artificial language like an automobile is an artificial horse."
Constructed languages are often divided into a priori languages, in which much of the grammar and vocabulary is created from scratch (using the author's imagination or automatic computational means), and a posteriori languages, where the grammar and vocabulary are derived from one or more natural languages. A posteriori planned languages can be further divided into naturalistic planned languages which follow the natural languages from which they are patterned closely to minimize learning time, and schematic planned languages, whose features are deliberately simplified or synthesized from various sources.
Fictional and experimental languages can also be naturalistic, in the sense that they are meant to sound natural and, if derived a posteriori, they try to follow natural rules of phonological, lexical and grammatical change. Since these languages are not usually intended for easy learning or communication, a naturalistic fictional language tends to be more difficult and complex, not less (because it tries to mimic common behaviours of natural languages such as irregular verbs and nouns, complicated phonological rules, etc.).
Taking all of the above into account, constructed languages can be divided up as follows from a simplified point of view:
- artistic languages (artlangs) - those intended to create aesthetic pleasure
- auxiliary languages (auxlangs) - those intended to be used for international communication
- logical languages (loglangs) - those intended to be an experiment in logic or philosophy
Proponents of particular constructed languages often have many reasons for using them. Among these, often cited is the famous but disputed Sapir-Whorf Hypothesis, which claims that the language one speaks essentially limits and drives the way in which one thinks. Thus, a "better" language should allow the speaker to reach some elevated level of intelligence, or to encompass more diverse points of view. Many question the validity of this claim.
Intended for general human use
Intended for machine assisted automatic translation purposes
Languages designed for knowledge representation
Languages of fictional worlds and peoples
See Fictional language.