Modal Verbs

Modal verbs in English are a type of auxiliary verb. These verbs are important in English because you can use them to indicate the modality of the main verb. Depending on which modal verb you use, the meaning of the sentence changes.

On this page, you have a complete overview of what modal verbs are, why you use them, and also some examples.

What are modal verbs?

Meaning of modal verbs

Modal verbs change the meaning of a sentence. They all have different meanings so you use them in different situations.

Can

Can is used to say when something is possible or when it’s allowed. It can also be used when someone has the ability to do something.

The negative form of can is can’t and is used when someone lacks the ability to do something, when something is not possible or when it’s not allowed. The full form of can’t is cannot. Take a look at the examples below:

Examples
I can speak 5 languages.
I can’t go to the party.
He can’t read.
We can listen very well.

Could

Could is mostly used as the past form of can. It’s commonly used with the following verbs: hear, smell, see, taste, feel and remember.

Examples
Could I go outside, please?
We could see the lake.
They could do what they wanted.
I could smell alcohol.

Must

Must can be used to express certainty. If you’re certain something is impossible, you use can’t.

Examples
They haven’t lived here for very long so they can’t know many people.
You have been walking all day so you must be tired.

Must can also be used when expressing your opinion about something that you think is appropriate in a particular situation.

Example
I haven’t seen her for ages so I must call her.

Have to

Have to is used when you are required to do something; when it’s an obligation or when it’s necessary.

Examples
I have to wear glasses for reading.
You can’t go left here so you have to go right.

May and might

May and might are used interchangeably because there is only a slight difference in meaning. You use these modal verbs when something is possible.

Examples
It might be true.
She might know.

The negative forms are may not and might not.

Examples
It might not be true.
She might not know.

In the past, you use may have (done) and might have (done).

Example
He might have been poor.

Should

Should is commonly used to give advice or to express an opinion.

Examples
You should call her.
He should go to bed early.

You can also use should to talk about something unexpected or something that doesn’t seem right.

Examples
She should be here by now.
I should already be a millionaire.

Should is also used to talk about expectations.

Example
She is smart so she should pass the exam.

If you want to use should in the past, you use should (not) have … This is used to talk about something that you didn’t do and regret that you didn’t do it. It can also be used when you did something and regret it.

Examples
I should have gone to the party.
He should not have stolen money.

Modal verbs overview

Modal verb	Use	Example
Can	Possibility Permission Ability	I can speak Chinese. You can use your phone in class.
Can’t / cannot	Impossibility Inability	He cannot read. They cannot talk to each other.
Could	Past form of can, usually in combination with: hear, smell, see, taste, feel and remember	I could smell gasoline. We could see Mount Everest.
Must	Certainty	He must be old.
Have to	Obligation	You have to be on time.
May	Possibility	They may trick us into buying something.
Might	Possibility	We might be lucky today.
Should	Advice Expectations	They should save some money for when they want to buy a house.

Exercises

• Can or Can’t Exercise 1
• Can or Can’t Exercise 2
• Can or Can’t Exercise 3
• Can or Can’t Exercise 4
• Can or Can’t Exercise 5

Related articles

• Verbs
• Irregular Verbs
• Present Tenses Overview
• Past Tenses Overview
• Future Tenses Overview