This article explores the use of two epistemic adverbs in Argentine Spanish, "quizás" and "capaz". While scholars have noted the existence of "capaz" as an epistemic adverb, it had not been systematically studied prior to this investigation. To examine the epistemic stance of the adverbs, 117 participants completed an experimental sentence completion task in which mood selection (i.e., percentage subjunctive use) was measured. The dependent variables considered were situational certainty and temporal reference, as well as adverb. Situational certainty (certain, not certain) and temporal reference (future, present, past) were communicated in written discourse scenarios that preceded the sentence to be completed, and the certain or not certain status was verified through a norming procedure. Through a mixed model analysis, findings indicated that temporal reference was the only significant dependent variable. Mood selection was significantly different in contexts with future, present, and past temporal reference. Future temporal reference was associated with the greatest subjunctive use and past with the least subjunctive use. The findings were similar for sentences with "capaz" and "quizás", indicating a similar epistemic stance based on current data.