This paper looks at some of the underlying reasons which might explain the uncertainty surrounding applied linguistics as an academic enquiry. The opening section traces the emergence of the field through its professional associations and publications and identifies second and foreign language (L2) teaching as its primary activity. The succeeding section examines the extent to which L2 pedagogy, as a branch of applied linguistics, is conceived within a theoretical linguistic framework and how this might have changed during a historical period that gave rise to Chomskyan linguistics and the notion of communicative competence. The concluding remarks offer explanations to account for the persistence of linguistic parameters to define applied linguistics