Dubitative mood

Dubitative mood (abbreviated DUB) is an epistemic grammatical mood found in some languages, that indicates that the statement is dubious, doubtful, or uncertain. It may subsist as a separate morphological category, as in Bulgarian, or else as a category of use of another form, as of the conditional mood of Italian.

An example can be taken from Ojibwe, an Algonquian language of North America. Verbs in Ojibwe can be marked with a dubitative suffix, indicating that the speaker is doubtful or uncertain about what they are saying. So aakozi means "he is sick," while aakozidog can be translated as something like "he must be sick; I guess he's sick; maybe he's sick; he might be sick."