What are modal verbs and the 5 best tips to learn them

Modal verbs can be categorized among the most important parts of English Grammar because these modal verbs give this possibility to the people to speak about different situations or that is better to say modal verbs meet a large part of the language needs. Modal verbs are auxiliary verbs that are used to indicate the ability, the possibility of an event, the permission to do a task or the obligation of a task. Semi-modal verbs are the same as modal verbs, With the difference that after them is the preposition to.

The modal verbs include can, could, be able to, must, have to, had better, may, might, shall, should, will, would, be able to, and ought to. Modal verbs are various in number and use.

Definition of modal verbs

Modal verbs include the verbs can, could, may, might, must, need not, shall / will, should / ought to. These modal verbs indicate ability, permission, possibility of doing something in the sentence. The form of modal verbs changes according to the time of the sentence,  so you should pay attention to the time of the sentence when using these modal verbs. Modal verbs are generally used only in the present tense in English, and of course, do not take the -s suffix in the third person singular. Unlike other auxiliary verbs, modal verbs do not take -s, -ing, -en or to.

Modal verbs describe the main verb of a sentence. how? For example, modal verbs say what a person can do, should, what is best and what can be done, or what might happen. Modal verbs are similar to auxiliary verbs, meaning that modal verbs are used in conjunction with the main verb of the sentence and have no meaning without the main verb. (The main verb that says what is being done or is happening)


She might live in Paris for ten years.

Some modal verbs such as have to, be able to and need are sometimes used in conjunction with another auxiliary verb:


Do you have to work tomorrow?

Other modal verbs such as can, should, and must, do not require an auxiliary verb.


What can I do?

You must not waste time.

Different kinds of modal verbs

Most linguists agree that the total number of major modal verbs is 9:

  1. Can
  2. Could
  3. May
  4. Might
  5. . Must
  6. Shall
  7. Should
  8. Will
  9. Would

Marginal modal verbs:

  1. need (to)
  2. ought
  3. have to
  4. be able to

The application of modal verbs

Modal verbs (Can / could / be able to)

A.These modal verbs are used to express and show a variety of ideas in English, for example, to show the ability or inability to do something.

To write the present and past of these modal verbs, use the following pattern:

Can + simple form of a verb


  • Tom can write poetry very well.
  • Am / is / are / will be + able to + The main (simple) form of the verb
  • Am not / isn’t / aren’t / won’t be + able to + simple form of verb


  • Sara is able to solve convoluted physics questions.
  • The rescue team will be able to help you in about 20 minutes.
  • I won’t be able to come with you next summer.
  • Past tense of can verb:
  • Could / couldn’t + the simple form of the verb
  • When I was a child I could climb mountains.
  • the past of be able to:
  • Was / were + able to + simple form of verb
  • wasn’t / weren’t + able to + simple form of verb
  • hasn’t / haven’t + been able to + simple form of a verb


  • I wasn’t able to visit her in her house.
  • He hasn’t been able to get in contact with the customer yet.
  • Note: After the modal verbs (can and could), the preposition to and the word will can not be placed. 

Example :

I can help you this afternoon.

Note: Cannot is a negative form of can. To negate the modal verbs like can, just add the word not to can. Consider the following 

Example :

He can’t play the piano.

Asking a question with can, to ask a question, just replace the verb can with the subject:


  • Can you play the guitar?
  • B.The modal verbs can / could are used to indicate the possibility or impossibility of an event.
  • Can / can’t + simple form of a verb
  • Could + simple form of a verb

Example :

You can catch that train at 10:43.

I could fly via London if I leave the day before.

C. Modal verbs (Can / could) also are used to allow or obtain permission. (Question and news sentences). But sometimes these modal verbs are used to get permission to do a certain thing that someone is allowed to do the same thing. Of course, being allowed to is much more formal and is mostly used to say rules and regulations.

Question (for informal sentences)

Can+subject +simple form of the verb 


Can you lend me ten dollars?

Question (polite)

could + subject+simple form of the verb 


Could I have your number?

D. Could also be used to present a proposal or use a proposal.


You could take a tour of the castle tomorrow.

Note: Can not be used for future tenses or all kinds of perfect tenses, Instead we can use to be able to which can be used in different tenses.


Jack’s been able to play piano for three years

I’ll be able to speak French when I finish the course.

Note: When we talk about a special event (not ordinary or general) in the past tense, only be able to can be used in the positive form of such a sentence. Modal verbs like can, can be used in the negative form of the sentence, but the positive case can only be able to.


I was able to get tickets for the movies.

Modal verbs may / might:

  • These modal verbs have many uses, including:
  • A- For official permits or prohibitions:
  • May / may not + simple form of verb


You may start your exam now.

B- Modal verbs may be used to express a polite request.

May+subject+The main form of the verb 


May I help you?

C- To express positive and negative probabilities using may or might modal verbs


We may go out for dinner tonight. Do you want to join us?

Our factory might get the order if the customer agrees to the price.

Note: There is a difference between modal verbs May and Might. In the common and oral uses of these two words, they are usually used to express probability, but there is a slight difference between these modal verbs.

May is used when something is possible and real or can be real.


She may lose her job.

I may have dessert after lunch.

Might is used to express something that is hypothetical, unrealistic, or unlikely to occur. 


If they hurry, they might get there on time.

If you had been punctual, you might have kept your job.

The modal verb, might, expresses conditions that are theoretical and not real, but may refer to conditions that may occur and are real. A simple way to remember this difference is to know that it might show a lower probability than may.

If the probability of something happening is low, we express it with might.

Key differences between modal verbs can and may. The following are the main differences between these two modal verbs:

May and can are both modal verbs, while the can is used to express a person’s ability or to talk about a variety of possibilities. But may is used to ask for permission or to give permission, as well as when there is a strong possibility in the middle. We can use both modal verbs may and can to allow or ask for permission. However, the use of may for this purpose is more common and formal.

We generally use can for informal requests and may for formal requests and permissions.

Modal verbs Shall / should / ought to:

These modal verbs are used to express an offer of help or a polite offer.


Shall we go for a walk?

Note: shall be used only with the pronouns I and We and in official places instead of Will.

B. Shoulds is used to predict an event or expectation to happen:


The proposal should be finished on time.

C.Used for advice :

Should / ought to + simple form of verb


You should check these documents before sending them out.

You ought to have your car fixed before the winter.

We use “had better” to refer to the present or the future; in fact, this structure is used to talk about actions that we think people should take actions that seem desirable in certain circumstances.


I’d better get back to work.

Had better is used to advise in specific cases.


I‘d better go to bed because I have to get up early in the morning. 

The form of the verb is (had) not (have). In informal situations, we usually shorten it to (d better ’).


It’s five o’clock. I’d better go now before the traffic gets too heavy.

Had better is a strong phrase. We use this phrase when we imagine that if someone does not do what is desirable or what is suggested, he/she will face negative consequences:


She’d better get here on time or she’ll miss the opening ceremony

Negative form and question had better

The negative form of this structure is had better not (‘d better not).


I’d better not leave my bag there. Someone might steal it.

The had better question form is created by moving the subject and had. In this case, the structure is similar to should but more formal.


Had I better speak to Tom first before sending this form off? What do you think?

Comparison between modal verbs shall and should

The difference between modal verbs shall and should is that shall say with certainty that something is going to happen, but should only say that something is likely to happen and nothing is certain.

The main differences between modal verbs shall and should:

Shall is an alternative to will, but only when the subject is I and We. Should was originally created to be a past tense, but these two words can not be used interchangeably or as another past tense! Shall is a modal verb that, except for a specific use that is an exception and mentioned above, in other cases can only come with I and We. Should is a modal verb that should be used with the subject and the main verb.

Shall is used in official writings to indicate the future tense. The main use of Should in informal writings, as in the past, is shall or a word of advice. Shall be used to express ideas and the law, and should be used to express personal opinion or advice. The narrator uses shall to talk about something that is going to happen in the future. Should say that something might have happened or has happened so far.

The verb should be used in the past tense according to the following formula.

should (n’t) have + p.p.

This indicates that the action that was done should not have been done or vice versa the action that was not done should have been done.

I failed my exam. I should have studied harder (= but I didn’t ).

I have a stomach ache. I shouldn’t have eaten so much (=but I did).

Modal verbs Must / have to / need to / don’t have to / needn’t 

Present and future:

Must / have to / need to + simple form of verb


You must have a passport to apply for the visa.

Sara has to apply for her visa by June 11th.

Past tense:

Had to /needed to + simple form


I had to work late last night.

I needed to eat a painkiller to fall asleep.

Note: modal verbs have to and need to both mean must, but need to is used where it is not necessary.

Must is used where an action must be taken. 


Thomas has lived in Paris for years. His French must be very good.

Use must or must not to prevent doing something.


You must not drive quickly.

The following pattern is followed when there is no need to do a task:

Don’t / doesn’t / didn’t + have to + simple form of verb


You don’t have to park the car.

You needn’t worry about me. I’ll be fine.

Note: The difference between mustn’t and don’t have to. 

Remember mustn’t mean prohibition, but doesn’t have to mean something that does not need to be done, but can be done if one wishes.


Children mustn’t play with matches.

They don’t have to go to work on Fridays.

Comparison of two modal verbs must and have to

Must means (must) and have to means (must – I have to). The modal verb, Must, has only one form, but has to become has to in the third person singular. The difference between these two modal verbs depends on the type of coercion.

Usually, if the compulsion is from the speaker, that is, the speaker feels the need to do something, then the must is used. But if coercion is imposed on the speaker from outside (for example, laws and regulations or a doctor, head of the department, teacher, etc. force the speaker to do something) then they have to be used. In other words, when using must, the speaker expresses his feelings, but when using have to, he expresses an external reality.


I must lose some weight. I’m getting fat.

I have to work late tomorrow.

Modal verbs Will / would / won’t

Will / would / wont + simple form of verb.


John will pick you up at 7:00 am.

Anna won’t be happy with the results of the math exam.

A.modal verbs will and would be used to express a request or a formal statement.


Will you please take the trash out?

I’d (I would) like to sign up for the match.

B.Modal verbs would or wouldn’t be used to express past habits:


John wouldn’t eat cake when he was a kid. He loves it now.

The difference between modal verbs should and must?

It should be noted that the amount of compulsion should be weaker than must.

Therefore, must is used for strong coercion and should be used for weak or moral coercion.


You should stop smoking. (= It would be a great idea)

You must stop smoking. (= It is essential that you quit)

There is usually always an emphasis on the present and the future, the present that comes after the modal verbs should be in the basic form or the simplest form, but modal verbs can be used with other forms of verbs as well. For example, one of the most common verb forms that can come after modal verbs is the use of present perfect time, which indicates probability and is used to refer to the past tense.


She must have bought that car.

Ellen could have thought he was late.

Another form that can be used after modal verbs is the continuous verb, which is used to refer to something that may / should / could happen in the present tense.


He may be studying for his physics exam.


Modal verbs play a very key role in English grammar since these modal verbs not only add variety to grammar but also modal verbs give the audience this power to express and show different situations and conditions like a possibility, permission, coercion, advice and so many other states which can be very helpful for the audience in different situations. Modal verbs can be used in different forms like simple, past, or future. 


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