This is a book for those encountering the field of communication disorders for the first time. It has come to be widely used as a foundation textbook in speech therapy courses. Following a review of the problems of terminology, the book discusses models of language disability and the advantages and disadvantages of the medical and behavioural models. Among the other topics considered are the communication chain and the classification of linguistic pathologies. The book also provides an integrated account of the contributions of the many disciplines and professions involved with language handicap. This second edition has an extra chapter reviewing the main trends in the subject in the 1980s.