Use this section for verbal auxiliaries, affixes, adverbs, and particles that indicate epistemic moods. Epistemic moods have the whole proposition in their scope and indicate the degree of commitment of the speaker to the truth or future truth of the proposition. They may be combined with any of the tenses, either in the same morpheme or in combinations of morphemes. The following definitions are taken from Bybee, Joan, Revere Perkins, and William Pagliuca. 1994. The evolution of grammar. Chicago and London: University of Chicago Press.