This is the first modern book-length empirical study and theoretical account of English truncatory processes. On the basis of a corpus comprising some 3000 derivatives, the book provides a systematic investigation of the structural properties of six different patterns of English name truncation and word clipping. All patterns are shown to be unique in terms of the structural requirements that they impose on their outputs. The book presents an optimality-theoretic account of the data in the framework of Prosodic Morphology. Pertinent theoretical claims are evaluated in the light of the empirical findings from English, leading to an analysis which can successfully predict canonical form in truncation and which incorporates systematic variability in output structure. This volume is a contribution to the study of both English word-formation and English phonology, and can be used by scholars working inside and outside OT alike.