Adam Ledgeway's research interests include the comparative history and morphosyntax of the Romance languages, Italian dialectology, Latin, Italo-Greek, syntactic theory, linguistic change and language contact. His research is channelled towards bringing together traditional Romance philological scholarship with the insights of recent linguistic theory. He has worked and published extensively on such topics as complementation, complementizer systems, auxiliary selection and split intransitivity, word order, Verb Second, configurationality, alignments, cliticization, clause structure, functional categories, the fine structure of the left periphery, differential object marking, the relationship between inflection and periphrasis, verb movement, adjectival positions, agreement, negation, subjects, causatives, voice distinctions, finiteness, imperatives, the development of demonstrative and deictic systems, determiner systems, possessives, grammaticalisation, parameters, Greek-Romance contact, and the syntax–phonology and syntax–pragmatics interfaces.