Interlanguage

In the field of second language acquisition, the term interlanguage refers to a learner's variety that conforms neither fully to the rules of the target language (the language the learner is aiming to acquire) nor to the rules of the learner's native language.

Comments
This term is closely associated with Larry Selinker's theory of second language acquisition (e.g. Selinker 1972, 1992).

Origin
The term was coined by Selinker (1972) and picked up quickly by other researchers (e.g. Richards 1972, Schumann 1974).

Synonyms
approximative system, transitional competence, language learner language