Definition - The phenomenon of a speaker alternating between two or more languages (or language varieties) during a single conversation.

Example -
For some good examples, click here to view NPR's Six Moments Of Code-Switching In Popular Culture

Etymology -
The term first appeared in Hans Vogt's 1954 review of Languages in Contact (1953) by Uriel Weinreich. He purportedly borrowed it from information theory.

Example Usages -

1. "It is common to find references to black speakers who code switch between AAVE [African American Vernacular English] and SAE [Standard American English] in the presence of whites or others speaking SAE. … For a black person who can switch from AAVE to SAE in the presence of others who are speaking SAE, code switching is a skill that holds benefits in relation to the way success is often measured in institutional and professional settings."
(Source: George B. Ray, Language and Interracial Communication in the United States: Speaking in Black and White. 2009) )

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