This book focuses on the most controversial area of phrase structure, the notion of specifier - a notion encompassing the traditional categories of subjects, possessors, determiners, auxiliaries, and adjuncts. It examines what place the notion has in the new theory and how the projection of specifiers is to be eliminated or extended. The contributors draw on empirical, theoretical research in cross-linguistic phenomena and first and second language acquisition. Contents: Introduction; Specifiers in Generative Grammar; Specifiers as Secondary Heads; Without Specifiers; Filling and Licensing Multiple Specifiers; EPP without Spec, IP; Spec-Head Agreement and Case in Arabic; The Specifier-Adjunct Distinction; The wh effect and Multiple Wh-fronting; Nominal and Verbal Projections; Dependencies and Extractions; Movement to Specifiers; Wh and the Locality of Feature Checking; Specifiers and Finiteness; Spec-Head Relationships in Child Swedish; Some Specs on Specs in L2 Acquistion.