Many children and adults experience significant breakdown in the use of language. The resulting pragmatic disorders present a considerable barrier to effective communication. This book is the first critical examination of the current state of our knowledge of pragmatic disorders and provides a comprehensive overview of the main concepts and theories in pragmatics. It examines the full range of pragmatic disorders that occur in children and adults and discusses how they are assessed and treated by clinicians. Louise Cummings attempts to integrate the fields of pragmatics, language pathology and cognitive science by examining the ways in which pragmatics can make a useful contribution to debates about cognitive theories of autism. The reader is encouraged to think in a critical fashion about how clinicians, experimentalists and theorists deal with pragmatic issues.