In studies of bilingual language acquisition, code-mixing refers to a developmental stage during which children mix elements of more than one language. Nearly all bilingual children go through a period in which they move from one language to another without apparent discrimination.King, Kendall A. 2006. "Child language acquisition." In R. Fasold and J. Connor-Linton (eds.) An Introduction to Language and Linguistics. Cambridge University Press. pp. 205-224. This differs from code-switching, which is understood as the socially and grammatically appropriate use of multiple varieties.
