Modal verbs
Modal verbs have special characteristics:
->They’re followed by bare infinitive (without to).
->No –s on the 3rd person singular.
->No –ing form.
->No auxiliaries in the interrogative and negative forms.
Modal verbs | Function | Substituting verbs | |
Can | Could | >Ability: He can speak English. >Ability (in the past): He could speak English, when he was younger. >Possibility: He can do his homework. >Permission: Can I ask you a question? >Offer: Can I help you? >Request: Could I borrow your pen? | To be able to To be capable of To be (im)possible to To be allowed to |
May | Might | >Permission (politeness): May I close the door, please? >Possibility: You might be sick? >Probability: It might snow. | To be allowed to To be likely to To be probable to Perhaps…will |
Will | Would | >Request (politeness): Would you mind borrowing me your pen? >Determination/intention: I’ll succeed. | To want To desire To be determined to |
Shall | Should | >Offer: Shall I call you? >Suggestion: Shall we study together? >Advice: You should do your homework. >Duty/moral obligation: Children should listen to their parents. | Do you want? Let’s To have to (morally) To be the (moral duty) To be better …would better… |
Must | - | >Negative deduction: He can’t have a good mark, because he didn’t revise his courses. >Obligation/duty: You must do your homework, whether you want or not. >Deduction (in the past: He had a good mark. He must have revised his courses. >Necessity: You must go to the doctor, if you’re ill. >Deduction: He’s smiling. He must be happy. | To have to To be obliged to To have the obligation To be certain Must have been |
Mustn’t | - | >Prohibition: You mustn’t eat in class. | To be forbidden to To be prohibited to |
Ought to | - | >Recommendation/moral obligation: You ought to revise your courses. | To have to |
Need/ Needn’t | - | > (Absence of) obligation/necessity: You needn’t swim. It’s too cold. >Necessity: You need to do your homework. | To be necessary Don’t need to Don’t have to |
Dare | - | > (Absence of) audacity: How dare you? | To have the courage to |
