Modal verbs show possibility, intent, ability, or necessity. Because they’re a type of auxiliary verb (helper verb), they’re used alongside the infinitive form of the main verb of a sentence. Common examples of modal verbs include can, should, and must.

Modal verbs can be tricky, but the good news is that they’re simple once you learn how they work. Below, we explain everything you need to know to use modal verbs with ease.

How are modal verbs used ?

Modal verbs are used to express certain hypothetical conditions, such as advisability, capability, or requests (there’s a full list in the next section). They’re used alongside a main verb to inflect its meaning.

Consider the difference between these two examples:

I swim every Tuesday.

I can swim every Tuesday.

The first example is a simple factual statement. The speaker participates in a swimming activity every week on Tuesdays.

The second example uses the modal verb can. Notice how the meaning changes slightly. The speaker does not necessarily swim every Tuesday; they’re saying that they are capable of swimming every Tuesday or that the possibility exists for them to swim every Tuesday. It’s hypothetical.

Modal verbs are quite common in English; you’ve seen them in action hundreds of times even if you didn’t know what they were called. The most frequently used ones are:

    can
    may
    might
    could
    should
    would
    will
    must

When are modal verbs used?

What special conditions do modal verbs indicate? Here’s a list, along with examples:

1. Likelihood
Some things seem likely to be true but can’t be stated as definite facts. In these cases, you can use the modal verbs should and must to show probability without certainty.
Example:
Her parents must be so proud.

My baby brother should be asleep by now.

2. Possibility
In a situation when something is possible but not certain, use the modal verb could, may, or might.
Judging by the clouds, it might rain today.
Example:
She may become the youngest pro soccer player ever.

3. Ability
The modal verb can expresses whether the subject of a sentence is able to do something. Likewise, the negative form, cannot or can’t, shows that the subject is unable to do something.
Example:
She can speak three languages but none of them well.

You can lead a horse to water, but you can’t make it drink.

4. Permission
If you want to ask permission to do something, start your question with can, may, or could. Traditionally, may is considered more formal and polite usage for permission; if you ask “Can I go to the bathroom?” it could be misinterpreted as “Do I have the ability to go to the bathroom?” However, in modern informal usage, may and can are both perfectly acceptable options for describing possibility or permission.
Example:
Students, you may leave early today.

Could I play too?

5. Suggestion/advice
What if you want to recommend a course of action but not command it? If you’re giving suggestions or advice without ordering someone around, you can use the modal verb should.
Example:
You should try the lasagna.

That guy should wear less cologne.

6. Command
On the other hand, if you want to command someone, use the modal verbs must, have, or need. With the latter two, the main verb does not drop the word to from its infinitive form.
Example:
You must wash your hands before cooking.

You need to be here before 8:00.

7. Obligation or necessity
Modal verbs can express a necessary action, such as an obligation, duty, or requirement. Likewise, the negative forms express that an action is not necessary. Use the same modal verbs as with commands: must, have, and need.
Example:
We have to wait for our boss to arrive before we open.

You don’t need to come if you don’t want to.

8. Habit
To show an ongoing or habitual action—something the subject does regularly—you can use the modal verb would for the past tense and will for the present and future. The phrase used to is also acceptable when you’re talking about a habit in the past.
Example:
When I lived alone, I would fall asleep with music.

I will arrive early to every meeting and leave late.

Complete the sentences with a modal verb from the box below. Sometimes more
than one answer is possible.

CAN – CAN’T – CAN’T HAVE – COULD – COULD HAVE – DON’T HAVE – HAD
BETTER – MIGHT – MUST – MUST HAVE – MUSTN’T – NEED – OUGHT –
SHOULDN’T

1. You ___________________ be exhausted after your long trip. Come in and have a drink.
2. John ___________________ taken your car keys. He hasn’t even left the house.
3. I won’t go out this afternoon because the weather forecast is not very good, and I
___________________ get wet.
4. You ___________________ to apply for the job yet. You can do it later this week.
5. I ___________________ left my wallet in the car. I can’t find it anywhere.
6. That ___________________ be Jake. It’s impossible. He said he was going to Spain.
7. You ___________________ step into the headmaster’s office without permission.
8. Tell your sister she ___________________ stay the night here if she wants to.
9. You have already drunken a glass of wine. You ___________________ not drive. Let me.
10. You ___________________ see the Eiffel Tower and the Louvre when you go to Paris.
11. I ___________________ to take orders from you. You’re not my boss!
12. When I was younger, I ___________________ run very fast.
13. Your cold is getting worse and you have a runny nose. You ___________________ to see
the doctor.
14. My husband is preparing dinner. He’s not a good cook so you ___________________
expect anything special.
15. Don’t leave your window open at night. Someone ___________________ climb in.
16. Brenda ___________________ be over thirty. She graduated a year after me and I’m only
26.
17. You ___________________ to come with me. I can manage on my own.
18. She ___________________ got lost. Otherwise she’d be here by now.
19. You must be more careful. You ___________________ been killed crossing the street
without looking.
20. I didn’t ___________________ to buy more groceries. We already had enough.

Fill in the blanks using MUST, CAN’T, MAY, MIGHT, COULD, SHOULD, SHOULDN’T and the PAST
FORMS of them ! First one is done for you .

1. Sally looks worried . She   MUST HAVE / MUST HAVE HAD   a problem with something (HAVE).
2. Bob ________________________ at school because I haven’t seen him all day (BE).
3. I ________________________ you the money. Why didn’t you ask me (LEND)
4. Mr Travis hasn’t come to work yet. He has never been late for work. He
________________________ the bus (MISS).
5. She knew everything about our plans. She ________________________ to our
conversation (LISTEN)
6. A: Will you come to my birthday party tomorrow afternoon ?
B : I’m sorry but I ________________________ because I have to look after my sister.
(COME)
7. Timmy is a very good boy. He isn’t naughty, so he ________________________ that
window. Somebody else ________________________ it (BREAK 2X)
8. The street is wet this morning . I’m not sure but it ________________________ last night
(RAIN).
9. She ________________________ like an angel when she was a child (SING)
10. A : I talked to your science teacher yesterday.
B : You ________________________ to her because she wasn’t at school yesterday.
(TALK)
11. Mrs White bought a new fur coat ! – She ________________________ the lottery (WIN).
12. He came home alone yesterday. You ________________________ him do that ; he
________________________ lost. (LET, GET)
13. He read the message but he ________________________ it (UNDERSTAND)
14. The singer has got a sore throat so she ________________________ at the concert (SING)
15. It ________________________ Jack I saw in the park yesterday, but I’m not sure about it
(BE).
16. We can’t wait any longer. Something ________________________ at once (DO).
17. Everyone shouted in fear. They ________________________ very afraid (BE).
18. A : I’m afraid Ted is watching TV again.
B : He ________________________ TV because his room is completely silent and dark. He
________________________ . (WATCH, SLEEP)
19. I can’t find my book . I ________________________ on the bus (LEAVE)
20. She ________________________ stupid. She teaches maths at the university (BE)
21. She ________________________ to school. It’s Saturday (GO).
22. You were stupid to go skiing here. You ________________________ a leg (BREAK)
23. He looked so tired when I saw him. He ________________________ so hard (WORK)
24. Tom ________________________ this because it is in French and Tom doesn’t know
French. (WRITE)

Choose the correct answer :

1. Why didn’t you help him? You ___ have done it.

A) must B) can C) could
D) were to E) was able to

2. Annie : ___ I phone you tonight?
   Becca  : Yes, you ___ .

A) may / may B) must / might
C) could / can’t D) shouldn’t / shouldn’t
E) have to / had to

3. But I ___ stay in England for six months, and not for a fortnight as
I had planned.

A) had to B) have to C) am able to
D) can E) shall have

4. -I ___ draw a circle with a pencil only, and you?
-Neither can I.

A) can’t B) can C) may
D) shan’t E) couldn’t

5. Last week I ___ go to town on business trip as the Ministry of Education had asked me to come.

A) had to B) might C) should
D) could E) was able to

6. If one person is careless with a library book, then it ___ be read
by others.

A) can’t B) couldn’t C) may
D) can E) mightn’t

7. After a book is written, it passes through the heads of very many
different workers. Each worker works carefully, for there ___ not
be any mistakes.

A) must B) couldn’t C) could
D) might E) has to

8. He tried, but ___ persuade nobody.

A) could B) couldn’t C) can
D) might E) won’t

9. People who know a foreign language ___ learn a second one
easily.

A) may B) should C) mustn’t
D) can E) needn’t

10. ___ I have a word with you, please?

A) may B) had to C) have to D) must E) am able to

11. At first I ___ skate well, now I ___ .

A) couldn’t / can B) may / can C) mustn’t / can
D) should / shouldn’t E) must / needn’t