The study of syntactic complexity and the identification of the elementary structural units involved have always been a component of research in the field of theoretical syntax. Still, these topics have recently acquired a higher degree of prominence and autonomy, which has led to an expansion in the ways syntacticians conceptualize syntactic representations and their interactions with other research topics. The Structure of CP and IP is the second volume in the Cartography of Syntactic Structures, a subgroup within the Oxford Studies in Comparative Syntax series. Funded by the Italian Ministry of Education, this research endeavor gave rise to the publication of the first such volume, The Functional Structure of DP and IP, which focuses primarily on the structure of nominal expressions and on certain aspects of clausal expressions. This second edited volume examines the structure of the clauses, with special reference to the inflectional domain (IP) and the left peripheral field of the clause (CP). With contributions by a select group of syntacticians, The Structure of CP and IP will be useful to scholars with an interest in Italian, Romance, and comparative syntax, and of substantial value to all linguists interested in contemporary research in generative grammar.