Planned language

The term planned language is used, when referring to international auxiliary language, especially to a posteriori languages, where the grammar and vocabulary are derived from one or more natural languages. See also Constructed language

The difference between schematic planned language and naturalistic planned languages is not a clear distinction but rather a continuum.

Schematic planned languages

A schematic planned language is a type of constructed language whose grammar and morphology have been deliberately simplified and regularized, with idiosyncrasies from source languages (if any) removed, in order to be simpler and more streamlined than those of the ethnic languages, even if this should make the language's vocabulary relatively unrecognizable to newcomers to the language.

Many studies have proven that this will make the language easier to learn and easier to use actively than any ethnic language, or even naturalistic planned languages. See also Propedeutic value of Esperanto. The best known example of this type of language is Esperanto.

Naturalistic planned languages

Naturalistic planned languages are constructed language specifically devised to reproduce the commonalities in morphology and vocabulary from a group of closely related languages, usually with the idea that such a language will be relatively easier to use passively -- in many cases, without prior study -- by speakers of one or more languages in the group. The term is most commonly used to apply to pan-Romance planned languages, though there have also been a few pan-Germanic, pan-Slavic and even pan-Celtic naturalistic planned languages, but without much success until now..

Since the creation of such a language often includes shared idiosyncrasies from the source languages, active use is more difficult than schematic planned languages, though because of grammatical simplification considerably easier than for ethnic languages of the same type.

The best known languages of this type are Interlingua and the now obsolete Occidental, which was almost totally absorbed into Interlingua.