 If the grammar can systematically and accurately describe the adult speaker's linguistic competence, it is called "descriptively adequate".If a grammar can describe the acquisition of this linguistic competence in a human child from its initial state to the final state, then it is said to have "explanatory adequacy".In Government and Binding theory, Chomsky is interested in the initial state of linguistic competence in a child, which is called a human's "biological endowment for language".