The relationship between structural linguists and applied linguists is notoriously uncomfortable; each tends to view the others' focus and methods with suspicion. Despite this uneasy relationship many TESOL-focused master's programs are housed in Linguistics Departments. This article reflects on my experience in 1 such department and makes suggestions for how the 2 halves of the department could be integrated to the advantage of each group. Formal linguistic theory has the potential to very usefully inform classroom practice, while the language classroom is an ideal location to investigate the mechanisms of second language acquisition and add to the body of knowledge on how language acquisition functions. Specific ways in which formal linguistic theory can be applied in the ESL classroom are discussed.