sociolinguistics, the study of language as it affects and is affected by social relations. Sociolinguistics encompasses a broad range of concerns, including bilingualism, pidgin and creole languages, and other ways that language use is influenced by contact among people of different language communities (e.g., speakers of German, French, Italian, and Romansh in Switzerland). Sociolinguists also examine different dialects, accents, and levels of diction in light of social distinctions among people. Although accent refers strictly to pronunciation, in practice a dialect can usually be identified by the accent of its speakers as well as by distinctive words, usages, idiomatic expressions, and grammatical features. Dialects reflect and may reinforce class, ethnic, or regional differences among speakers of the same language. In some cases difference of dialect shades into difference of language. Where the line between them is not clear, groups that are linguistically distinct are considered to speak different dialects of the same language if they can generally understand each other, although what constitutes this mutual intelligibility is itself not always clear. For example, someone speaking Mandarin may not be able to understand the spoken form of another Chinese dialect but can read it, since the written form of all Chinese dialects is universal; Serbs and Croats, on the other hand, speak essentially the same language but use different alphabets to write it. Individuals sometimes deliberately change their dialect as a means of improving their social status. Speakers of any dialect or any language may modulate their vocabulary and level of diction according to social context, speaking differently in church, for example, than on the playground; social activities that tend to shape the language of those engaging in it are sometimes called registers.
See R. A. Hudson, Sociolinguistics (1980); P. Trudgill, Dialects in Contact (1986); H. Giles and N. Coupland, Language: Contexts and Consequences (1991).