Universal grammar (UG), in modern linguistics, is the theory of the innate biological component of the language faculty, usually credited to Noam Chomsky. The basic postulate of UG is that there are innate constraints on what the grammar of a possible human language could be. When linguistic stimuli are received in the course of language acquisition, children then adopt specific syntactic rules that conform to UG.[1] The advocates of this theory emphasize and partially rely on the poverty of the stimulus (POS) argument and the existence of some universal properties of natural human languages. However, the latter has not been firmly established, as some linguists have argued languages are so diverse that such universality is rare,[2] and the theory of universal grammar remains controversial among linguists.[3]