Covering the proceedings of the Child Language Seminar, held 4-6 September, 1998, in Sheffield, UK, this text aims to provide an overview of late-20th century research into child language development and disorders. Its 26 chapters, written by leading authorities around the world, address many of the key issues which are currently exercising the minds of child language researchers, and which are likely to motivate research for some time to come. A key theme of the book is the nature of language acquisition in children whose learning capacity is in some way impaired, and what this can tell us about language development more generally. The main topics covered are: cross-linguistic perspectives on language acquisition; the relationship between innate linguistic capacity and the specific properties of the language being acquired; syntax; argument structure; verbs and verb morphology; phonology; pragmatics and discourse; and literacy.