This paper deals with the phenomenon of code switching among bilinguals. Whereas previous studies of code switching have, however, concentrated on instances in which code alternation can be correlated with a change in social occasion, this paper uses examples from the speech of Mexican-American and Afro-American bilinguals to focus on those instances in which seemingly random language mixture is found in informal situations in which the minority language is considered normal. The author argues that such switching is not random but serves definite and clearly understandable communicative ends. Underlying this phenomenon is seen to be the process of foregrounding (the highlighting of a word or a syntactical of phonological form by using its outside of its normal context), and the various contextual meaning derived through such alternation are discussed in some detail. The author concludes that an understanding of the extent to which minority groups use code alternations as a verbal strategy in everyday interaction and of the extent to which such groups are sensitive to the relationship between language and context is more important to the success of programs aiming at biculturalism and bilingualism than a knowledge of the ways in which nonstandard dialects differ grammatically and phonologically from Standard English. (FWB)