The Science: Social Sciences: Linguistics: (Bilingualism Linguistics )

Bilingualism is a subtopic within the study of Linguistics (the study of languages and its use). Specifically, it is the study of people who speak two languages. Common phenomena that occur for bilinguals is code switching, forming language mixtures, and dual identity. Bilingualism Linguistics Social Sciences Science.

Multilingualism is the use of two or more languages, either by an individual speaker or by a community of speakers. (wikipedia)