All the auxiliary verbs except "be, do and have" are called modal verbs. Unlike other auxiliary verbs, modals only exist in their helping form; they cannot act alone as the main verb in a sentence. Be, do, and have also differ from the other auxiliaries in that they can also serve as ordinary verbs in a given sentence. The modal verbs are: can, could, may, might, must, shall, should, ought to, will and would.

MODAL VERBS : Modal verbs are special help verbs. They add extra ‘meaning’ to the main verb. Most modals have more than one use: Verbs Examples and Uses Can can I use your phone? Permission Can you quote me a price for CIF New York requests Passengers can take a small bag onto the plane with them :possibility/ability I can’t find my boarding card :inability Could could I interrupt a moment? :Permission Could you speak up?: Requests We could ask for volunteers :suggestions May may I borrow your car?: Permission Might it might be possible to reduce the price:Future possibility Will I’ll tell him to phone you back :promises How many people will work here? :Future facts There won’t be much space. :Predictions Would would you speak more slowly please ?: requests What would you like to drink ?: offers Would like to come to a party ? I’d love to. : Invitations What time would suit you? : Suggestions Would you reduce the price? : suggestions Shall shall we ask for volunteers ? : suggestions Shall I call a taxi for you?: Offers What shall I do? : Asking what to do Should I think we should teach the French sales staff English.; Recommending action The government should increase taxes on petrol. : Saying what is right or correct Must passengers must make sure their bags are clearly labelled :obligation Passengers mustn’t carry guns or explosives: prohibition

What are modal verbs? These are verbs used before the base forms of other verbs to denote obligation or certainty. (Base form = infinitive without 'to') For example: I must learn. He can go. They could fall. We will come. The first verb in each case is the modal verb, the second is the base form. I hope this helps.