In this paper, the authors look at the importance of Task-Based Learning and its connection with the study of English in Japan. Swain’s “Three functions of Output” is looked into, and tested as part of the Task-Based Learning (TBL)system. In particular, Matsuka uses a vocabulary exercise in a Communication class to illustrate how Task-Based Learning can promote retention of words and their meanings, as shown by the high marks students gained for vocabulary studied through the TBL system.