But consider “the importance of time and patience cannot be overestimated”. Cannot is used in its deontic (obligation) sense, meaning that we must not underestimate the importance of time and patience. Consider the following: “the importance of time and patience cannot be underestimated”. As we spend much time thinking and talking about the irrealis, modal auxiliaries are very common.Ī further distinction is to be made between epistemic and deontic modals, which distinguish between possibility one the one hand and obligation on the other. The modal auxiliaries’ job is to express possibility (hypothesis, futurity, doubt) and necessity (by inference, such-and-such must necessarily be the case) that is, matters beyond the factual here and now.
Why only quasi? Because the nine modals sit before the base form: I shall go, I could go, etc., but with ought/need/has we have to insert a to: I ought to go, it needs to be done, it has to be April (said at the onset of a shower, prompting inference). There are also quasi-modal auxiliary verbs: ought to, need to, has to. There are nine modal auxiliary verbs: shall, should, can, could, will, would, may, must, might.
