Robert D. Van Valin Jr. (born February 1, 1952) is an American linguist and the principal researcher behind the development of Role and Reference Grammar, a functional theory of grammar encompassing syntax, semantics, and discourse pragmatics. His 1997 book (with Randy J. LaPolla) Syntax: structure, meaning and function is an attempt to provide a model for syntactic analysis which is just as relevant for languages like Dyirbal and Lakhota as it is for more commonly studied Indo-European languages.
Instead of positing a rich innate and universal syntactic structure (see Universal Grammar), Van Valin suggests that the only truly universal parts of a sentence are its nucleus, housing a predicating element such as a verb or adjective, and the core of the clause, containing the arguments, normally noun phrases, or adpositional phrases, that the predicate in the nucleus requires. Van Valin also departs from Chomskyan syntactic theory by not allowing abstract underlying forms or transformational rules and derivations.