There are a lot of tomatoes in the fridge.You must stop when the traffic lights turn red.Modal verbs are followed by an infinitive without "to", also called the bare infinitive. You should / ought to revise your lessons There are plenty of tomatoes in the fridge. Fill in can, have to, may, might, must, need, should or (not) allowed to. I might go on holiday to Australia next year. You must stop when the traffic lights turn red. He go to the dentist when he has toothache. You be tired because you have worked very hard. Here is a list of modals with examples: Modal Verb You not vacuum the carpets because Carol has already done it. Modal phrases (or semi-modals) are used to express the same things as modals, but are a combination of auxiliary verbs and the preposition to. Modal verbs are used to express functions such as: Modal and Modal Phrases (Semi-Modals) A modal is a type of auxiliary (helping) verb that is used to express: ability, possibility, permission or obligation. The verbs or expressions dare, ought to, had better, and need not behave like modal auxiliaries to a large extent and may be added to the above list Use of modal verbs: Here is a list of modal verbs: can, could, may, might, will, would, shall, should, must They are used to indicate modality and allow speakers to express certainty, possibility, willingness, obligation, necessity, ability.They are always followed by an infinitive without "to" (e.i.Here are some characteristics of modal verbs: They have a great variety of communicative functions. They are different from normal verbs like "work, play, visit." They give additional information about the function of the main verb that follows it. Modals (also called modal verbs, modal auxiliary verbs, modal auxiliaries) are special verbs that behave irregularly in English.