Robert Van Valin is the principal writer behind
Functional Linguistics[?], which is an offshoot of the
cognitive linguistics field pioneered by
Langacker[?]. His 1997 monograph 'Syntax: structure, meaning and function' is an attempt to provide a method 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 separate layer of
deep structure[?] to explain departures from
Chomsky's canonical word order, Van Valin suggests that the only truly universal parts of a sentence are its nucleus, generally a predicating element such as a verb or adjective, and the arguments, normally
noun phrases[?], that the nucleus requires. Van Valin also departs from Chomskyan syntactic theory by denying the existence of the
verb phrase.