Evidentiality has been extensively studied in linguistics for its function in coding the source of knowledge or for expressing the speaker’s attitude towards knowledge. However, few studies examine how evidential marking is sensitive and responsive to the unfolding talk and actions of the participants in social interaction. Analyzing audio and video data of naturally occurring conversations in Korean in a conversation analysis framework, this article demonstrates how the speaker often makes the choice of evidential marking or shifts the choice of (...) evidential marking according to the participant’s response, achieving certain interactional functions. The speaker makes a strategic choice to use the experiential evidential marking -telako or shifts from zero-evidential marking to overt experiential evidential marking -telako for the same proposition to achieve entitlement, objectivity, or detachment regarding his claim. This study shows that, in social interaction, the choice of the speaker’s evidential marking is relative and interactively organized rather than static and predetermined. (shrink)