What are Modal Verbs?

MODAL VERBS

A modal verb is a type of auxiliary or helping verb that helps the main verb by indicating the mood of the subject. Modal verbs indicate ability, possibility, obligation, or necessity.

The main modal verbs are can, could, may, might, will, would, must, shall, and should.

There are also quasi-modal, or semi-modal, verbs. These are a subcategory of modals, especially when they function in their negative and interrogative form.

Quasi-Modal Verbs

The main quasi-modal verbs are dare, had better, need, ought to, used to, and would rather.

Examples of Modal Verbs

Look at the examples of modal and quasi-modal verbs in the charts below.

Modal Verb Type or Mood Example
can ability/permission (informal) You can borrow my pencil.

Can I borrow your pencil?

 

could

permission, suggestion, request, past ability, future possibility He could leave early if his boss would allow him.
may probability, permission (formal) You may borrow my pencil.

May I borrow your pencil?

might probability/ possibility (future) I might ask my boss for permission to leave early.
will wish/willingness He will agree to it.
would request/past habit/possibility If I had the time, I would travel more.

Would you help me with my homework?

When I was young, I would listen to the radio all day long.

must necessity/obligation You must go out and search for a job.
shall intention/suggestion Shall you help her with her luggage?

I shall help her if you want me to.

should necessity/advice I should exercise more often.

QUASI-MODAL VERBS

Quasi-Modal Verb Type or Mood Example
dare ability (negation) I dare not go without permission.
had better advice/obligation You had better not go alone.
need request (negation) You need not ask again.
ought to advice/probability/obligation You ought to visit your grandmother more often.
used to previously/habitually I used to go all the time.
would rather intention/ willingness I would rather eat pizza than tacos.

MORE ABOUT MODALS

Modal verbs are placed first in the verb phrase, after the subject, and are followed by a verb in the base form.

  • He could leave early. (Could is the modal and leave is the main verb.)
  • I should exercise more often. (Should is the modal and exercise is the main verb.)
  • You may borrow my car. (May is the modal and borrow is the main verb.)
  • I must help my friend. (Must is the modal and help is the main verb.)

The verb following the modal may be a main verb or an auxiliary verb like be or have.

  • He might be late tomorrow. (Might is the modal and be is the auxiliary.)
  • She should have studied more. (Should is the modal, have is the auxiliary, and studied is the main verb.)

Modal verbs are used in conditional sentences.

  • If I had the time, I would travel more. (If I had the time is the if clause in a conditional, would is the modal and travel is the main verb.)

Modal verbs are used in inverted sentences, especially in interrogative sentences. (Verb before subject)

  • May I take your car tonight? (May is the modal. Notice it comes before the subject, I. Take is the main verb.)
  • Would you help me with my homework? (Would is the modal. It comes before the subject, you. Help is the main verb.)

Modal verbs appear in negative form by adding the adverb “not” after the modal verb.

  • I dare not ask for permission. (Dare is a quasi-modal, not is an adverb of negation, and ask is the main verb.)
  • We would rather not eat at the restaurant again. (Would rather is a quasi-modal, not is an adverb of negation, and eat is the main verb.)
  • Shouldn’t you call before you go? (Should is the modal, not is an adverb of negation in the contracted form, call is the main verb. This sentence is in inverted order because the modal shouldn’t comes before the subject, you.)

 

5 INTERESTING FACTS ABOUT MODALS

Modal verbs only have one form.

  1. They have no infinitives using the “to” form. (INCORRECT: to can, to could, to may, to might, etc.)
  2. They have no –ing form, present participle. (INCORRECT: canning, coulding, maying, mighting, etc.)
  3. They have no past tense form. (INCORRECT: canned, coulded, mayed, mighted, etc.)
  4. They do not change form for person. (INCORRECT: he cans, she cans, it cans, he coulds, she coulds, it coulds, etc.)
  5. They cannot be used with another modal. (INCORRECT: Had I known, things may would have been different.)

Remember that a modal verb helps the main verb by indicating the mood of the subject.

Download the handout on modals.