Picture a small child saying: "Can’t, shan’t, won’t!" They are using modal verbs to show their feelings and attitude to something. Maybe they are refusing to go to bed or eat their peas.
Modal verbs are easy to spot because there are so few of them. In addition to must, shall, will, should, would, can, could, may and might, we can add ought to and have to. If we are told that we ...