By using the methodological framework of conversation analysis, this study combines a grounded study of interactional linguistics focusing on L2 speakers' interactional competence in the use of Korean sentence-ending suffix -ketun. Based on the previous studies which examined the use of -ketun in L1 Korean speakers’ conversation, this study analyzes data taken from different levels of Korean language classroom interactions, with close attention to the learner's usage of the target suffix in formulating a dispreferred response. The findings of the study demonstrate that the L2 advanced students' use of -ketun is much closer to that for L1 speakers in constituting a dispreferred response while claiming epistemic primacy. On the other hand, extremely low frequency in the use of -ketun is a distinctive linguistic-pragmatic features that characterizes use of -ketun by L2 speakers at lower levels of competence. The advanced students' diversification may be an indicator of their more adaptive, context-sensitive conduct, suggesting an increased interactional competence. Close scrutiny of the use of -ketun in this study aids to reveal whether and to what extent its interactional use by L2 speakers of different proficiency levels approaches that of L1 speakers.

From a conversation-analytic perspective, this paper examines the ways in which the Korean sentence-ending suffix (SES) -ketun is used in naturally occurnng sp아<en Korean 이 scourse. Focusing on the question of how the practice of informing implemented by the ketun-utterance provides a basis for the sequentially implemented action of account-giving (Kim & Suh 2뼈)， it a n따yzes (i) the nature of the information marked by -ketun in terms of how it is grounded, (ii) the sequential contexts where the informing sequence that -ketun generates is embedded, and (iii) features of the ketun -marked account with reference to the practices of formulating non-negotiable upshot, evo싸 ng positionally relevant identities, unpackaging information geared to enlightening the address얹. and stance-shifting. These practices are analyzed as being constitutive of the action-organizational features of the ketun-marked account, whose upshot is proposed to be that of evo써 ng and managing the information gap or disparity in knowledge asseπed by the speal<er to exist between the partlclpants.