Abstract
<jats:title>Abstract</jats:title> <jats:p>Bilinguals change their way of communicating when they are with monolinguals and when they are with bilinguals who share their languages. While they avoid using their other language(s) with monolinguals, they may call upon it (or them) when interacting with bilinguals, either by changing over completely to the other language(s) or by bringing elements of the other language(s) into the language they are speaking. In other words, they change their language mode which, at the cognitive level, implies the change of the state of activation of their languages and language‐processing mechanisms. This entry describes language mode and its impact on language behavior, gives evidence for it, discusses various types of bilinguals affected by it, examines language mode as a confounding or control variable in research, and ends with a few words on models and what needs to be studied further.</jats:p>