This article reveals the interaction patterns that commonly occur between instructors and pre-service teachers in TEFL classes. 34 sessions of nine instructors belonging to three TEFL programs of different universities were observed and transcribed. Data was analyzed under two methodologies, Ethnomethodological Conversation Analysis and Self-evaluation of Teachers Talk. Findings reveal that TEFL classes are divided into transactional episodes that do not necessarily happen in the same order and that are composed of interaction patterns with an extended pedagogical purpose. Further analysis of these interaction patterns unveil that both instructors and pre-service teachers come into the classroom with a pre-planned conversational agenda which contains pedagogical and interactional purposes. Imbalance between both agendas create paradoxes that send mixed messages to pre-service teachers about how to interact with instructors in class activities. These findings opens a discussionon the manner in which the identified interaction patterns create a type of classroom interaction that is more transactionalthan spontaneous or genuine. This situation portrays a lasting legacy in pre-service teachers since they may interact with their future language students in the same manner that they learnt in their TEFL classes.