While parentheticals attract constant attention, they very rarely constitute the main subject of monographs. This book provides a comprehensive account of reduced parenthetical clauses (RPCs) in three Romance languages. Typical French RPCs are je crois, disons, je dirais, je pense, je sais pas, and je trouve. The research draws on 22 corpora of spoken French, Italian, and Spanish comprising a total amount of 3,975,500 words. Its results consist in a typology of the relevant expressions in the three languages, in the understanding of their pragmatic function and of the factors influencing their use, and in the description of their syntactic and prosodic properties. Other findings are that RPCs are not restricted to statements but also occur in questions and that belief verbs are not as frequent as commonly assumed. Although the book is about Romance parentheticals, its conclusions are relevant for other languages.