This book examines some of the ways in which linguists can express what native speakers know about the sound system of their language. Intended for the absolute beginner, it requires no previous background in linguistics, phonetics or phonology. Starting with a grounding in phonetics and phonological theory, the book provides a base from which more advanced treatments may be approached. It begins with an examination of the foundations of articulatory and acoustic phonetics, moves on to the basic principles of phonology, and ends with an outline of some further issues within contemporary phonology. Varieties of English, particularly Received Pronunciation and General American, form the focus of consideration, but aspects of the phonetics and phonology of other languages are discussed as well. This new edition includes more discussion of Optimality Theory and a new glossary of terms. It has been updated throughout to take account of the latest developments in phonological theory, but without sacrificing the book's ease of use for beginners.