In contact linguistics, a mixed language is, loosely speaking, a language with multiple origins. While all languages include at least some loanwords or other instances of influence, usually most of the basic vocabulary and grammar derives from a single source; the term "mixed" is conventionally reserved for cases where this is not true. Different authors differ on its exact definition, and in particular on the inclusion of pidgins and creoles.
For Bakker (1999:195), a mixed language is one that shows "positive genetic similarities, in significant numbers, with two different languages". This definition excludes most pidgins and creoles, whose lexicon typically derives mainly from a single language and whose grammar cannot be traced to any single language.
For Thomason (1988:8, 2001:158), a mixed language is one whose lexicon and grammar do not both derive primarily from the same source language. This definition includes pidgins and creoles, since much of the grammar does not derive from the lexifier. Those languages which Bakker terms mixed, Thomason terms bilingual mixed languages.
Most known (bilingual) mixed languages (for example, Para-Romani varieties, Media Lengua, Maa) feature a split between a vocabulary primarily derived from one language and a grammar primarily derived from another. However, in two known cases, Michif and Copper Island Aleut, the grammar itself shows a large-scale split.
- Bakker, Peter. 1999. A Language of Our Own: The Genesis of Michif, the Mixed Cree-French Language of the Canadian Métis. Oxford: Oxford University Press.
- ed. Bakker, Peter and Yaron Matras. 2003. The Mixed Language Debate: Theoretical and Empirical Advances. Berlin: Mouton de Gruyter.
- Thomason, Sarah G. & Terence Kaufman. 1988. Language Contact, Creolisation, and Genetic Linguistics. Berkeley: University of California Press.
- Thomason, Sarah G. 2001. Language Contact: An Introduction. Edinburgh: Edinburgh University Press.