This study examines how task type influences the distribution and functional use of discourse markers (DMs) in Korean university EFL learner interaction. Two task-based activities were compared: a structured Spot-the-Difference (SPOT) task and an openended Decision-Making (DEC) task. Based on Fung and Carter’s (2007) multi-functional framework, five DM categories—response tokens, interpersonal, referential, structural, and cognitive—were analyzed across dyadic interactions. Contrary to expectations, overall DM frequencies were comparable across the two task types; however, functional analysis revealed distinct interactional profiles for each. Specifically, the results showed clear functional differentiation: SPOT elicited substantially more response tokens, reflecting an interactional orientation toward maintaining conversational flow, tied to its convergent, visually supported design. In contrast, DEC elicited higher frequencies of interpersonal, structural, and referential DMs, suggesting a greater reliance on reasoning, negotiation, and collaborative meaning-making. A chi-square test of independence confirmed a significant association between task type and DM distribution. These findings support claims that task complexity and communicative purpose shape learners’ discourse behavior and DM deployment (Tavakoli & Foster, 2008). Pedagogically, the study highlights the value of selecting tasks strategically to promote targeted DM functions, suggesting that more complex, open-ended tasks foster richer pragmatic engagement. Directions for future research are also proposed.