ABSTRACT
In order to arrive at a theory of L2 acquisition, it is essential to have a theory of what it is that the learner acquires; in other words, a theory of language (a linguistic theory) is necessary (Gregg, 1989; White, 1989). Furthermore, language pedagogy is, in its turn, affected by our theories of language and language acquisition, although it is not necessarily the case that linguistic theory or second language acquisition (SLA) theory will have direct pedagogical implications. Indeed, the relationship between linguistic theory or SLA theory and language pedagogy is like the relationship between other “pure” and “applied” sciences: the pure theory may turn out to have significant applications, but it is not usually developed with applications in mind. However, with more than a decade of UG-oriented second language (L2) research behind us, particularly research that has looked into the question of whether UG is available to L2 learners, more and more of this research addresses the question of whether L2 input can still trigger principles and parameters of UG, raising the question of the role of L2 input in and out of the classroom and the effectiveness of different kinds of pedagogical intervention in triggering properties of UG. An advantage of applying linguistic theory to SLA and to issues of language pedagogy is that the theory makes specific claims about the nature of language and hence testable predictions about the nature of interlanguage and the relationship between a mental grammar and input.
