This paper describes how Applied Linguistics (AL) seminar students that are proficient in languages other than English intern as classroom assistants (CAs) in foreign language classrooms. The CAs gain useful insights from the seminar on theoretical and pedagogical approaches, methods and techniques in L2 pedagogy and then apply this knowledge through their practical experience as mentors/tutors to language learners. A diverse range of second/foreign language courses thus benefit from these "participant-observers". Seminar students report on their experiences through written and oral exercises, discussions and presentations, and finally through journal reflections which are first reviewed by their supervising language instructors before submission to the seminar professor. A review of these journal entries shows that placing informed classroom assistants into a second/foreign language classroom can be very helpful to language instructors, their students and the CAs themselves, as long as communication lines are clear and assumptions about theoretical perspectives and practical tasks are understood. Such a course would be a fruitful supportive option in Applied Linguistics programmes with access to second/foreign language programmes that would benefit from informed classroom aides.