Generative phology has many adherents, and t a few critics, but surprisingly few good expositors. Francois Dell provides here both a general introduction and a detailed illustration of the operation of the theory in practice, introducing the main concepts of phology and its place in the grammar of a language. The approach is in the tradition of Chomsky and Halle, emphasizing the interactions between syntax, morphology and phology, and aiming at the discovery of general principles which shape the sound patterns of all languages. He then applies these concepts to particular case studies, on the maxim that the best way to understand a system of this kind is to use it. This was first published as Part I of Les regles et les sons (Hermann, 1973).