This book is about the possibilities and achievements of children, adolescents and adults who have developmental disorders that make their development of speech difficult or very delayed and who therefore need to develop communication and language with other means than speech. For some, the difficulties are temporary in childhood, others continue to communicate with alternative communication systems throughout adulthood. This comprehensive and accessible volume offers guidance based on current knowledge about typical and atypical language development for all those supporting families and professionals involved with children, adolescents and adults who may benefit from using augmentative and alternative communication (AAC) systems. The text covers all major issues and gives a thorough introduction to factors that are important when choosing communication systems, vocabularies of manual signs and graphic symbols. It guides the reader in assessment strategies, adaptation of the language