A particular phenomenon has been observed to operate in the field of foreign language teaching. Teachers of English (the subgroup on which this study focused) do not seem to take an interest in the more general theories of learning, laying more stress, instead, on how teachers teach, rather than on how students learn. This fact, it was hypothesized, partly explained the primacy (and the popularity) among practitioners of the methods and approaches to teach English, in detriment of a systematic reflection on the processes of learning. Nevertheless, the lack of proper information on how the learner learns did not seem to conspire against what might roughly be defined as good classroom practice, in the same way that knowledge of the theories of learning did not seem to be a determinant factor in securing a better quality of language teaching. A sample of 100 teachers in the City of Buenos Aires and Greater Buenos Aires (Argentina) was surveyed through a self-administered questionnaire to assert whether practitioners possessed a sound knowledge of not only the methods that they purported to use in their classrooms but also of the theories of learning that underlie them and whether the procedures that they used in their professional practice reflected those particular methods and were in keeping with the theories of learning that they advocated. The analysis of the data collected in the survey has shown that a considerable number of respondents evidenced unsatisfactory or insufficient knowledge of the contemporary theories of learning and of how these theories influence classroom processes, but that this lack of satisfactory knowledge in the area of learning theories was not an obstacle for the respondents to adequately identify and apply in their classrooms the techniques and strategies that were construed to correspond with the tenets of the particular method they had chosen to use in the courses they taught. The study also concluded that the lack of solid knowledge about the theories of learning manifested by the classroom teachers surveyed was partly due to the lack of proper information received in the course of their Teacher Education and partly due to their lack of interest in this area as evidenced in their choice of graduate teacher development courses. Additionally, this study presents a review of the most salient theories of learning of the twentieth century, Behaviourism and Constructivism, and their relationship to the methods for language teaching that they underpin