ABSTRACT
This chapter considers some of the major areas which provide data for the study of phonology: variation; historical change; and language acquisition. It is concerned with dialects – varieties of speech within a single language; and to some extent with style: varieties of speech within a single speaker. The chapter discusses methods for comparing differences of pronunciation. In pre-generative linguistics, this meant describing each non-standard dialect independently, on its own terms, without reference to a 'standard' from which it 'deviated' in some way. Social dialects not only distinguish between different groups of speakers; they also have an influence on the speech of individuals at all levels of society. A speaker may adopt a more or a less prestigious variety, depending on the situation or the occasion. The description of realizational differences between accents thus calls for a fine ear and fairly precise techniques of measurement.
