Patois, although without a formal definition in linguistics, can be used to describe a language considered as nonstandard. Depending upon the instance, it can refer to jargon or slang, as well as to pidgins, creoles, and/or dialects. In many cases, class distinctions are drawn between those who speak patois and those who speak the standard or dominant language.

Many of the vernacular forms of English spoken in the Caribbean are referred to as patois (occasionally spelled in this context as patwah). Often these patois are popularly considered "bastardizations" of English or slang, however, in many cases, such as with Jamaican English, they are better classified as a creole language; in fact, in the Francophone Caribbean the analogous term for local variants of French is creole.

In France, patois has been used to describe non-French languages spoken in France, such as Breton and Occitan. This usage encompasses the view of such languages as being backwards and "country," and is considered by speakers of those languages as very offensive. (See also: Languages of France.)

Other examples of patois, include Trasianka, Sheng, and Tsotsitaal .