The study of Romance languages can tell us a great deal about sentence structure and its variation in general. Focusing on the dialects of Italy – including the islands of Sardinia and Sicily – the authors explore three thematic areas: the nominal domain, the verbal domain and the left periphery of the clause. The book gives fresh attention to the dialects, arguing that they offer an unprecedented degree of variation (not found, for example, in Germanic languages). Analysing a host of new data, the authors show how the dialects can be used as a test-bed for investigating and challenging received ideas about language structure and change. Coherent and wide-ranging, this is a vital resource for those working in syntactic theory, historical linguistics, and Romance languages.