The Romance languages and dialects constitute a treasure trove of linguistic data of profound interest and significance. Data from the Romance languages have contributed extensively to our current empirical and theoretical understanding of phonetics, phonology, morphology, syntax, semantics, pragmatics, sociolinguistics, and historical linguistics. Written by a team of world-renowned scholars, this Handbook explores what we can learn about linguistics from the study of Romance languages, and how the body of comparative and historical data taken from them can be applied to linguistic study. It also offers insights into the diatopic and diachronic variation exhibited by the Romance family of languages, of a kind unparalleled for any other Western languages. By asking what Romance languages can do for linguistics, this Handbook is essential reading for all linguists interested in the insights that a knowledge of the Romance evidence can provide for general issues in linguistic theory.