Universal grammar theory proposes that humans possess innate faculties related to the acquisition of language. The definition of universal grammar has evolved considerably since first it was postulated and, moreover, since the 1940s, when it became a specific object of modern linguistic research. It is associated with work in generative grammar, and it is based on the idea that certain aspects of syntactic structure are universal. Universal grammar consists of a set of atomic grammatical categories and relations that are the building blocks of the particular grammars of all human languages, over which syntactic structures and constraints on those structures are defined.
Robert F. Barsky