What Is a Modal Verb? | Definition & Examples

A modal verb (also called a modal auxiliary verb) is used along with a main verb to express possibility, ability, permission, or necessity. For example, in the statement “you must leave,” “must” is a modal verb indicating that it’s necessary for the subject (“you”) to perform the action of the verb (“leave”).

The modal verb “will” is used to form the future tense, indicating an action that has not yet occurred (e.g., “I will clean the garage”).

Examples: Modal verbs in a sentence
We should listen to some music.

Can you drive me to the airport?

Amanda might practice her German.

How are modal verbs used in sentences?

Modal verbs are used along with a main verb to indicate ability, necessity, possibility, and permission. In sentences containing modal verbs, the main verb typically takes the infinitive form. Modal verbs come before main verbs and never change form.

Examples: How to use modal verbs
I might walk to work today.

You may have as many cookies as you’d like.

Lina must order tickets in advance if she wants to go to the theater.

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Modal verbs list

Below is a table that illustrates some of the various uses of modal verbs. Note that modal verbs are very commonly used in a wide variety of senses—this table doesn’t cover every possible usage.

Modal verb Function Example
Can Indicate ability

Indicate possibility

Indicate permission (informal)

Make a request (informal)

Javi can play the guitar.

We can drive or walk.

You can borrow that book.

Can I have some water?

Could Past form of “can”

Indicate possibility

Make a polite request

She could speak French.

You could become a chef.

Could you tell me the time?

May Indicate possibility

Indicate permission (formal)

Make a request (formal)

Dana may arrive late.

You may enter.

May I respond?

Might Indicate possibility I might order pizza.
Must Indicate obligation

Indicate likelihood

Cyclists must wear helmets.

You must be very proud.

Shall Indicate a future action (normally used only with “I” and “we”)

Ask a question (normally used only with “I” and “we”)

I shall attend.

Shall we arrange a meeting?

Should Make a suggestion

Indicate likelihood

You should watch that film.

Tom should be at the office.

Will Indicate a future action or event

Make a polite request

Fay will book the venue.

Will you get the door?

Would Past form of “will”

Make a polite request

She would often work late.

Would you call back later?

Modal verbs and auxiliary verbs

Modal verbs are classed as a type of auxiliary verb. Auxiliary verbs are used along with a main verb to express tense, mood, or voice. However, unlike modal verbs, regular auxiliary verbs follow subject-verb agreement and must be conjugated for tense and mood.

Examples: Auxiliary verbs in a sentence
Mary was building a sandcastle.

Gordon has burned the toast.

Do you know what time it is?

Modal verbs can be used along with auxiliary verbs to refer to possible past, continuous, or future action.

When a modal verb is followed by another auxiliary verb (e.g., “have,” “be”), the main verb takes either the past participle form (typically ending in “-ed,” “-n,” or “-t”) or the present participle form (ending in “-ing”).

The modal verb “will” is used in all aspects of the future tense (e.g., “I will talk,” “you will be traveling”).

Examples: Modal and auxiliary verbs combined
He should have asked me first.

You may be wondering what I mean.

Farrah will have finished work by then.

Modal verbs and mood

The grammatical mood of a verb indicates the intention of the sentence. Modal verbs and auxiliary verbs are used along with a main verb to express mood.

Grammatical mood Function Example
Indicative State a fact “Lana is drinking coffee.”
Imperative Express a command or a request (often with a negative auxiliary verb) Don’t forget to call.”
Interrogative Ask a question Would you open the window?”
Conditional Express a condition “You should leave now if you want to get the bus.”
Subjunctive Express a wish, doubt, or hypothetical situation “If you were free, we could watch a movie.”

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Other uses of modal verbs

Modal verbs have various other functions in English. They can also be used:

Indirect speech

Modal verbs are used in indirect speech to indicate what someone else said. While most modal verbs stay the same when used in indirect speech, the past form of some modal verbs is used instead (e.g., “can” becomes “could”).

Examples: Modal verbs and reported speech
Darren said “I will visit on Saturday.”
Darren said he would visit on Saturday.

Pria said “we should go to France.”
Pria said we should go to France.

Negative statements

In negative statements containing modal verbs, the adverb “not” comes immediately after the modal verb and before all other verbs. The negative form is often contracted (e.g., “would not” becomes “wouldn’t”).

Examples: How to use modal verbs
Tera can’t focus because her brother is playing the drums.

You mustn’t play football inside the house anymore.

Emphasis

In everyday conversation, people sometimes place emphasis on a modal verb to refute a previous statement or question. The emphasized word is often italicized when written down.

Examples: Modal verbs emphasizing a statement
Why can’t you be nice?
I can be nice!

You won’t finish the project on time.
I will finish it on time!

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If you want to know more about commonly confused words, definitions, common mistakes, and differences between US and UK spellings, make sure to check out some of our other language articles with explanations, examples, and quizzes.

Frequently asked questions

Modal verbs (also called modal auxiliary verbs) are used along with a main verb to express ability, possibility, necessity, and permission. They are a type of auxiliary verb.

For example, in the statement “I can drive,” “can” is a modal verb indicating that the subject (“I”) has the ability to perform the action of the verb (“drive”).

Is it “would of” or “would have”?

“Would” is a modal verb that’s often used along with the auxiliary verb “have” to indicate that something was possible in the past but no longer is (e.g., “She would have been a professional athlete if she hadn’t broken her leg”). It can be contracted to “would’ve.”

People sometimes mistakenly write “would of” because of its similar pronunciation. However, “would of” is never correct.

What does “may” mean?

“May” is a modal verb used to indicate possibility (e.g., “I may miss the bus”), make a request (e.g., “May I have a drink?”), or indicate permission (e.g., “You may sit down”).

Sources in this article

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This Scribbr article

Ryan, E. (2023, December 06). What Is a Modal Verb? | Definition & Examples. Scribbr. Retrieved April 24, 2024, from https://www.scribbr.com/verbs/modal-verb/

Sources

Aarts, B. (2011). Oxford modern English grammar. Oxford University Press.

Butterfield, J. (Ed.). (2015). Fowler’s dictionary of modern English usage (4th ed.). Oxford University Press.

Garner, B. A. (2016). Garner’s modern English usage (4th ed.). Oxford University Press.

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Eoghan Ryan

Eoghan has a lot of experience with theses and dissertations at bachelor's, MA, and PhD level. He has taught university English courses, helping students to improve their research and writing.