This book provides a readable and clearly articulated introduction to the field of Cognitive Linguistics. It explores the far-reaching implications of Eleanor Rosch’s seminal work on categorization and prototype theory, extending the application of prototype theory from lexical semantics to morphology, syntax, and phonology. The third edition is fully revised and updated to include the considerable developments in Cognitive Linguistics since 1987. It covers recent research on polysemy, meaning relatedness and metaphors, as well as expanding the discussion of syntactic categories and the relevance of computer simulations.