After reviewing, from a grammaticalization perspective, the main stages in the evolution of Italian object clitic pronouns, the book discusses the distinctive morphosyntactic, semantic, and pragmatic features of Italian clitics. In particular, the book offers an original study of the most common examples of so-called verbi procomplementari, verbs which are characterized by the incorporation of clitics that no longer function as pronouns, and which are widely used in present-day Italian. Their emergence involves both grammaticalization of the clitic pronoun into an obligatory element, and lexicalization of the verb+clitic sequence. This study is essentially descriptive and maximally data-driven. The discussion of grammaticalization and lexicalization is reduced to the essentials and aims primarily at defining how these terms, which have received different and at times divergent interpretations, are employed in the book. The book is accessible to a wide and varied readership, which includes Italian and Romance linguists of functional and formal orientation, Italian language scholars, grammaticalization scholars interested in new case studies, as well as students of language change and variation.