What Is a Modal Verb? | Definition & Examples
Modal verbs (aka modal auxiliary verbs) are used alongside the main verb to provide additional context regarding possibility, intention, permission, or obligation.
For example, “will” is a modal verb that indicates a person’s intention to do something or that something is certain or expected to happen. It’s used to form the future tenses (e.g., “we will be there soon”).
You must look both ways when crossing the road.
Amir might bring some snacks.
How are modal verbs used in sentences?
Modal auxiliary verbs come before the main verb in a sentence and provide additional context regarding the possibility of something or a person’s control over something. They don’t change their form (e.g., for subject-verb agreement), and the main verb is usually in the infinitive form.
This may be the best movie I’ve ever seen.
We will visit Maurice on the way to the grocery store.
Modal verbs list
Most modal verb meanings can be divided into two categories:
- Possibility (likelihood and ability)
- A person’s control over something (intention/volition, obligation/necessity, requests, permission, offers, and suggestions)
The same modal verb can have different meanings depending on the context. For example, “may” can be used both for permission and likelihood.
This list contains all the modal auxiliary verbs and their most common uses with examples.
| Modal verb | Use | Example |
|---|---|---|
| Can | Permission
Request Ability (present and future) Possibility—something we believe is usually but not always true (present and future) |
You can come too if you like.
Can you pass the salt? I can play the accordion. Dogs can be very loyal. |
| Could | Permission
Request Possibility—possible but uncertain or unknown Ability (past and future) |
Could I come?
Could you pass the salt? My father could know. I could skate when I was young. |
| May | Permission (formal)
Possibility—possible but uncertain or unknown |
You may leave.
My father may know. |
| Might | Permission/request (very formal)
Possibility—possible but uncertain or unknown |
Might I take your name?
My father might know. |
| Must | Obligation—a requirement or command
Possibility—strongly expected but not certain |
You must submit your paper by November 7th.
You must be very proud. |
| Shall | Can be used in place of “will” in future tenses (usually for human subjects)
Offer or suggestion Obligation or command |
I shall give her a piece of my mind.
Shall I start the movie? You shall listen when I speak. |
| Should | Possibility—likely or expected without being certain
Obligation—something that is preferable or expected but isn’t necessarily required or done Advice or suggestion |
They should arrive any minute.
People should brush their teeth twice a day. You should come to the party. |
| Will | Future tenses: Possibility (certain or expected to happen) Intention/volitionRequest |
They will arrive at 8 o’clock.
I will tell him what I think. Will you marry me? |
| Would | Request
Volition (past, usually negative) Talking about the future in the past Conditionals and hypothetical scenarios Past habits Softening an opinion or a suggestion to make it less direct or more polite |
Would you pass the salt?
He wouldn’t pass the salt. I would stop if I were you. We would talk every night. I would suggest a different size. |
Modal verbs and auxiliary verbs
The three primary auxiliary verbs (aka helper verbs) are “be,” “do,” and “have.” They are used alongside the main verb to change its tense, mood, or voice and need to be conjugated for tense and subject-verb agreement.
Serena didn’t like waiting.
Tianna had worked at the company for three years.
Modal verbs also appear alongside main verbs to provide additional context, so they are also known as modal auxiliary verbs. They don’t change their form.
Modal verbs can be used with auxiliary verbs to change the tense.
Even though main verbs following modal verbs are usually in their base form, when a modal verb is followed by an auxiliary verb, the main verb uses the past participle or present participle form.
You should have checked the instructions.
We might go by train.
We might be going by train.
Other modal expressions
There are other modal expressions (sometimes called phrasal modals, semi-modals, or semi-auxiliaries) that have characteristics of both auxiliary verbs and modal verbs.
While modal verbs don’t change their form, phrasal modals are often based on an auxiliary verb or a normal verb and change their form accordingly. They usually express similar meanings to modal verbs (e.g., possibility and obligation), and always precede the main verb.
I will buy a new car.
We have to call them tomorrow.
We must call them tomorrow.
Modal verbs and mood
The grammatical mood (aka modality) of a verb or sentence indicates the attitude or intention of the speaker.
In some languages, verbs will take different forms to indicate different moods. In modern English, however, the same verb form can be used for different moods, and moods are often expressed through constructions. These can include auxiliary verbs and modal verbs, which can change the mood of a sentence by expressing the possibility or necessity of something, for example.
| Mood | Intention | Example |
|---|---|---|
| Indicative | Make a factual or neutral statement
Ask a question (interrogative) State a condition (conditional) |
We are watching a movie.
Does Jamie like dogs? We can go home if you’re tired. |
| Imperative | Make a demand or request | Don’t tell her what I said. |
| Subjunctive | Express a wish, demand, suggestion, doubt, or hypothetical scenario | I think that you should rest. |
It is necessary that students wear the proper uniform.
Students must wear the proper uniform.
Some languages have other moods, such as the potential mood to indicate the probability of something, that are only expressed through modal verbs in English.
More advice on using modal verbs
Below are a few pointers on using modal verbs in the following scenarios:
In indirect speech
When reporting what someone else has said, “can” and “will” may become “could” and “would” as the reported speech took place in the past. Other modal verbs will stay the same.
Andrew said I could call him later.
Mom said “you should do your homework.”
Mom said I should do my homework.
In negative statements
To make a negative statement containing a modal verb, add the adverb “not” after the modal verb and before the main verb (the exception is “can,” which becomes “cannot” instead of “can not”). The modal verb and “not” is often contracted (e.g., “can’t”).
That mightn’t be the best idea.
For emphasis
You can place emphasis on a modal verb to contradict a statement or question. It’s often italicized in writing.
I will be there.
You can’t dance.
I can dance.
Frequently asked questions about modal verbs
- Is it “would of” or “would have”?
-
Although “would of” is sometimes used in colloquial speech, the correct form is “would have” or the contraction “would’ve” (which can sound very similar to “would of” when spoken).
“Would” is a modal auxiliary verb and “have” can either be an auxiliary verb or a main verb. Modals and auxiliaries are used with a main verb to change its tense, mood, or voice.
When “would have” modifies a main verb, it often describes a conditional or hypothetical scenario in which something didn’t happen but could have happened if the situation had been different (e.g., “we would have gone to the beach if the weather was nicer”).
- What does “may” mean?
-
“May” is a modal verb that modifies the main verb to express either possibility or permission.
You can use “may” in formal situations to ask for or give permission (e.g., “May I borrow your pen?” “You may leave now”).
You can also use “may” to talk about something that is possible but uncertain or unknown (e.g., “the shop may be shut already”).
