This study investigates the interaction between evidentiality and epistemic certainty mediated by Korean sentence-ending(SE) markers within a speaker-listener interaction model. An experiment involving 350 native Korean speakers examined how SE markers influence the perception of visual evidentiality and certainty from both interlocutors’ perspectives. The results revealed a distinct cognitive asymmetry: while speakers systematically modulated their certainty according to evidentiality types, listeners processed the two dimensions independently. Mediation analysis further demonstrated that the direct influence of a speaker’s evidential access on listener’s certainty was negligible. Instead, speaker’s certainty served as a robust mediator, indicating that evidential signals primarily function to establish the speaker’s internal certainty, which then transfers to the listener’s certainty. Furthermore, a significant suppression effect was identified; when speaker’s certainty was controlled, high evidentiality negatively impacted listener’s certainty, meaning that “witnessed but uncertain” information is interpreted as a signal of unreliability. These findings demonstrate that Korean SEs function beyond grammatical markers, serving as a dynamic socio-cognitive interface that negotiates trust between speakers and listeners.
Yi et al. (Sat,) studied this question.