Comprehension Analysis on the Discourse Marker Function of English -ly Type Epistemic Stance Adverbials

English -ly adverbials (LY) with epistemic modality are frequently used as discourse markers (DM) in spoken language. In this paper, LY DM is defined as an epistemic stance marker. The experiment for this study aims to analyze Korean EFL learners' comprehension of LY used as a DM on the basis of the hypothesis that they would perceive LY differently from how English native speakers perceive them. In order to conduct the experiment, previous studies on DMs were thoroughly examined to establish the theoretical framework. Based on the framework, the Discourse Marker Interpretation Test (DMIT) was designed. The research data collected through the test were analyzed using quantitative methods. Additionally, interviews were conducted to supplement the interpretation of the research results. The experiment mainly determined that, unlike English native speakers, who properly interpreted LY with their DM function, Korean EFL learners are inclined to interpret LY used as DMs simply with their lexical meanings (the dictionary definition). Results suggest that there is a high possibility for Korean EFL learners to commit more errors when encountering LY DMs.