The investigation of sentential complementation focuses on properties of sentences that are embedded in other sentences. This book brings together a variety of studies on this topic in the framework of generative grammar. The first part of the book focuses on infinitival complements. The author provides new perspectives on raising and control, longstanding problems in infinitival complementation. He then examines the problem of clitic ordering in infinitives in Romance languages. The second part of the book addresses various aspects of Wh- sentences: extraction from negative and factive islands, agreement in relative clauses, and the relation between French relative and interrogative qui and que.