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 ...

needn't In the other format, need behaves as a modal verb, like can, could, must should, etc. It has the same forms as modal auxiliary verbs: the third person singular has no s, questions and ...