The document discusses code-switching, which is when speakers alternate between two or more languages in a single conversation. It defines code-switching and provides examples. Specifically, it discusses that code-switching can occur for reasons like socioeconomic status, survival, expressing solidarity, compensating for language deficiencies, or exclusion. It also describes different types of code-switching like intra-sentential, inter-sentential, and extra-sentential switching. Additionally, it mentions emblematic or tag switching, which involves very short switches to signal group membership.