In bilingual and multilingual communities, it is common to observe the phenomenon of "language mixing," where speakers incorporate elements from multiple languages into their speech. Sociolinguists have developed the concepts of matrix language and embedded language to describe and analyze the complex patterns of language mixing that occur in these contexts. In this article, we will look at the ideas of matrix language and embedded language, talk about how they help us understand bilingual speech, and show how important these ideas are in sociolinguistic research.