This paper debates epistemic stance in spoken L2 production. Employing a subset of the Trinity Lancaster Corpus of spoken L2 production, it explored the speech of 132 advanced L2 speakers from different L1 and cultural backgrounds taking part in four speaking tasks: one mainly monologic presentation task and three interactive tasks. The inquiry centered on three types of epistemic forms: adverbial, adjectival, and verbal expressions. The outcomes displayed a systematic variation in L2 speakers’ stance-taking choices across the four tasks. The biggest difference was found between the monologic and the dialogic tasks, but differences were also found in the distribution of epistemic markers in the three interactive tasks. The variation was accounted for in terms of the interactional demands of individual tasks. The inquiry also found evidence of considerable inter-speaker variation, pointing out the existence of individual speaker style in the use of epistemic markers. By centering on social use of language, this paper tries to add to our grasp of communicative competence of advanced L2 speakers.