Pidgins and Creoles, languages that evolved as means of communication (often for trading purposes) between groups without a common language. A pidgin is usually based on two different languages (although some have influences from other languages as well), but with a sharply curtailed vocabulary (often 700 to 2,000 words) and grammar. Usually one language (the lexifier) contributes the majority of the vocabulary leading the pidgin to be described as, for example, “English-based”. A pidgin has no native speakers and is used as a lingua franca, or common language, in a region where different peoples mix but have no shared language. Pidgins are often viewed as “broken” or inferior languages but they are in fact creative adaptations of natural languages, and have a grammatical structure and rules of their own. Some pidgins, known as expanded pidgins, may become so useful that they develop a formal role in communication and are sometimes given official status by a community as a lingua franca, as in the case of Hiri Motu, a Motu-based pidgin that is an official language in Papua New Guinea. A characteristic of pidgins, however, is that they do not live for very long (compared with other languages), often dying out or becoming creolized within a century.

Among languages that have given rise to pidgins are English, French, Spanish, Italian, Zulu, and Chinook (because of former colonialism many pidgins have arisen out of a European language). In a pidgin, the meaning of words may be different to that in the language they were taken from: the English word belong becomes blong (“is”) in Chinese Pidgin and bilong (“of”) in Melanesian Pidgin. Many concepts are expressed by phrases, for example, lait bilong klaut (“lightning”, literally “light of cloud”) in Melanesian Pidgin. Borrowings from other languages may be added; Melanesian Pidgin, for instance, has two forms of the word we: mipela, “I and others but not you” (from mi, “I”, plus plural ending -pela, derived from “fellow”); and yumi, “we, including you”.

If a pidgin is used frequently enough and develops more roles in a community it can be passed on by parents to children and so becomes a mother tongue; it is then called a creole, and its vocabulary, grammar, and other linguistic features undergo an expansion as the functions of the language expand. Creoles often exist alongside another, standard (and often official), language, and so attitudes towards them can be stigmatized. However, sometimes creoles themselves become so prominent in society that they undergo a formal standardization process, thus decreolizing the language. Examples of creole languages include French-based Haitian Creole French, spoken in Haiti and the Dominican Republic; Iberian-based Papiamento, spoken in the Netherlands Antilles and Aruba; English-based Nigerian Pidgin English, spoken in Nigeria and intelligible with some other West African creoles; and Tok Pisin, the recently creolized Melanesian Pidgin (English-based) of Papua New Guinea, where it holds official status.