The English "modal verbs" are **will, would, can, could, may, might, must, should, ought (to)** and the now rare **shall**. The forms and grammatical usages of modal verbs differ in several important ways from those of non-modal verbs --- e.g. modals are uninflected -- as grammars are obligated to show in terms of an intelligible system,. Modal verbs express modal or unreal (irrealis) situations: those which are not yet existent, viz. futurative - - willed or forbidden, denied and so on. Modal need and dare convey modal overtones, viz. volitional force, advice or warning. Contrast needn't (and obsolescent daren't) with doesn't need to and doesn't dare to, and note the advisory vs. neutral thrust of the respective variants. Contrast negated modal needn't with doesn't before non-modal need . Another syntactic difference is that the modal takes a short infinitive (i.e. without to).