Communication strategies (CSs) are what learners use “to overcome the inadequacies of their interlanguage resources” (Ellis, 1994, p. 396). Although the importance of CSs is widely recognized, “little has been discovered about the developmental nature of CSs in L2 production” (p. 402). This paper will present the results of a yearlong study monitoring the developmental sequence of Japanese first year university students’ usage and understanding of CSs in their English classes. In essence, this study examines how students learn to use CSs as tools to mediate their learning of English from a sociocultural perspective. Students were taught new CSs every other week and encouraged to use those CSs along with the previously taught ones during paired conversations. The study used a mixed method approach to data collection, which included weekly student journals, surveys, interviews, video-recorded conversations, transcripts, self-evaluations, speaking test scores, and retrospective verbal reports recorded in students’ native Japanese. As a longitudinal study it highlights students’ use and understanding of CSs in a way that previous short-term studies were perhaps not able to identify. The study indicates that teaching CSs helped students to demonstrate increased independence (self-regulation) in performing tasks. Such a study is expected to shed light on how students, through strategy training, develop “the quality and quantity” of collaborative dialogue as they move from peripheral participants to full participants in tasks (see Swain, Kinnear, & Steinman, 2011).