Language Development and Language Impairment offers a problem-based introduction to language impairment in the pre-school years, from the vantage point of typical language development. The authors begin with an overview of issues in the study of language development, and an introduction to some of the causes of language impairment. This is followed by a thorough examination of the infrastructure for speech and language laid down in the first year of life, and the potential for speech or language deficits should the trajectory of development in this period be deflected, diverted or delayed. Subsequent chapters deal separately with development and impairment in the sound system, in the acquisition of vocabulary, in the grammatical system, and in conversation and narrative. Chapters are organised around a series of problems - case histories, datasets, quotations, conversations, etc.  - which serve to focus the discussion of a specific topic in typical development or impairment. By considering in detail the major features of the foundational years of  language development, Language Development and Language Impairment offers invaluable insights into the optimal and sub-optimal evolution of a childs linguistic competence.