This article reports on an experimental study that investigated the effects of different conditions of listener backchannels on the fluency of L2 speakers. The participants were 15 advanced Chinese learners of Korean who performed oral tasks in three different backchannel conditions: (1) verbal + nonverbal (V+NV), (2) nonverbal-only (NV), and (3) no backchannels (NB). The verbal backchannels included “[ŋ~] (Non lexical verbal form)”, “[ne]”, “[ɑ]”, “[ɨm]” while the nonverbal backchannels involved head nodding. Fluency was assessed via three temporal measures: Rate A, Rate B and MLR. The data was statistically analyzed using SPSS 25 package. The results showed that 15 Chinese participants in the NV condition were more fluent than in the V+NV or NB conditions. However, no significant differences were found between the V+NV and NB conditions. These results suggest that nonverbal backchannels may facilitate the fluency of advanced Chinese learners of Korean during oral tasks depending on the nature of backchannel use in their L1 and sociocultural environments. The present research theoretically broadens the scope of both fluency and backchannel studies and provides valuable data and methods for empirical studies on backchannels to Korean.

Interaction in Korean Conversation. The Sociolinguistic Journal of Korea, 12(1). Among many topics in interactional linguistics, the research on reactive tokens has explored complex processes in which participants collaborate and develop each other's talk in a moment-by-moment fashion. The present study investigates properties of backchannels as tokens of social interaction in Korean conversation by adopting methodology of frequency analysis and conversation analysis. Through a frequency analysis of backchannels such as 'e', 'a', 'um', and 'ung', this research shows that backchannels most frequently occur at complex transition-relevance places where turn-constructional units and intonation units converge. Examination shows that major functions of backchannels in conversation can be summarized as in the three categories: (i) to signal passive recipiency of the on-going turn, showing attentiveness or acknowledging what is being talked about, (ii) to signal that the recipient is in agreement or of the same opinion with the current speaker, and (iii) to express recipient's affiliative or emotional attitudes such as sympathy toward the information provided, among others. Finally, this research shows that interaction-based study of backchannels in their interactional contexts can provide a better way of understanding communicative strategies and the relationship between conversation and grammar than do other traditional or formal approaches to grammar.