The backchannel 'sodesu-ka' is considered a signal which functions to indicate one's understanding of information. This study examines how a hearer uses 'sodesu-ka' in actual conversations. The data used in this study is from the conversations of the intermediate level learners in KY corpus. The results of this investigation show that the form of 'sodesu-ka' appears with emotional expressions. This implies that 'sodesu-ka' as a backchannel has a function as a communicative strategy. It also has an active function as a procedural device in situations using languages.
