Have you ever heard your young child mix two languages in the same sentence, or even within a word? If so, there’s no cause for concern. In fact, “code switching,” or jumping between two languages within a single conversation, is a normal aspect of language development for children learning two or more languages simultaneously.
Researchers agree that code switching is not only normal, but used as an early strategy for learning. Furthermore, children will usually maintain the grammatical rules of each language, actually demonstrating advanced language skills. Most children will outgrow mixing languages by age three, then able to fully distinguish between them. Then they may consciously choose to switch according to each social situation.
Code switching is also common within bilingual families and communities. One benefit of bilingualism, according to the California Department of Education, is that people can navigate between languages with ease to emphasize or clarify a point, “especially when a word or concept does not exist in one of the languages… As children get older, switching languages represents a complex accomplishment in language, reflecting a knowledge of an advanced system of rules.”
This information on ‘code switching’ was summarized and quoted from the book Preschool English Learners: Principles and Practices to Promote Language, Literacy, and Learning.