Modal Auxiliary Verbs

                                   Modal Auxiliaries

 Modal auxiliaries (Modal verbs) 


 A modal verb is used with other verbs to express actionsevents or situations that exist only as conceptions of the mind - permissionspossibilitiescertaintyabilitywishes,obligations etc.

  A modal verb is an auxiliary verb that can be used to change the grammatical mood of a sentence.

 The key way to identify a modal verb is by its defectiveness (they have neitherparticiples nor infinitives).

Modal verbs:

shall and should

will and would

may and might

can and could



The following are not modal verbs but may be used for a similar purpose

ought to and had better

used to


going to

dare and need

have(got) to

be able to

Characteristics of Modal Verbs

1.They have no –s in the third person singular.


・She can speak French. (correct)

・She cans speak French.(incorrect)

2.Modal auxiliaries do not have infinitives or participles .

You cannot say shalling, shalled, to shall, to must or to may.

3. They take negation directry.(add "not")


・can not (can't)

・could not (couldn't)

・will not (won't)

・would not (wouldn't)

・may not (mayn't)

・might not (mightn't)

・shall not (shan't)

・should not (shouldn't)

・must not (mustn't)

4. They are followed by the “*bare infinitive 

*A bare infinitive is an infinitive without "to" 

5. Their interrogation is to invert the subject and modal verbs. 


You can swim well.
Can you swim well?

I may go to the party.
May I go to the party?

6. They can’t co-occur (go with). 

 Example  ・You may can go.

Position of Modal Verbs 

 Modal verbs always appear in the first position at the beginning of the verb phrase in English. 

 Unlike other verbs, modal verbs do not show tense or number. The eight possible verb phrase combinations that contain modal verbs in English are:

1.modal verb + base form = will see
2.modal verb + be + present participle = will be seeing
3.modal verb + have + past participle = will have seen
4.modal verb + be + past participle = will be seen
5.modal verb + have + been + present participle = will have been seeing
6.modal verb + have + been + past participle = will have been seen
7.modal + be + being + past participle = will be being seen
8.modal verb + have + been + being + past participle = will have been being seen

Function of Modal verb

Some of the more common definitions (in no particular order) of the modal verbs in English are:

can – ability, permission, possibility, request

could – ability, permission, possibility, request, suggestion

may – permission, probability, request

might – possibility, probability, suggestion

must – deduction, necessity, obligation, prohibition

shall – decision, future, offer, question, suggestion

should – advice, necessity, prediction, recommendation

will – decision, future, intention, offer, prediction, promise, suggestion

would – conditional, habit, invitation, permission, preference, request, question, suggestion