Modal Verbs in English: List, Functions & Sentence Examples

Modal verbs are used daily in English—to offer suggestions, ask polite questions, express uncertainty, or show what someone must or might do. They don’t describe action directly, but they shape its meaning.

Whether you’re writing instructions, holding a conversation, or making a request, modal verbs help you express your intention with clarity. This guide explains how modal verbs work, when to use them, and how they differ from regular helping verbs, with examples that reflect real-world usage.

What Are Modal Verbs?

Modal verbs are auxiliary verbs that express meanings such as ability, advice, possibility, necessity, or permission. They always appear before the base form of the main verb and never take endings like –s, –ed, or –ing. Their function is to add nuance to the verb that follows.

For example, in the sentence, “You should check the details before signing,” the modal verb should doesn’t describe an action itself—it adjusts the meaning of check, suggesting advice or recommendation.

Unlike main verbs, modals do not work alone in a sentence. They need a base verb after them to complete the idea. Their role is not to describe what someone is doing but how, when, or under what conditions the action happens.

List of Modal Verbs in English

English has nine core modal verbs. These are short, unchanging verbs that always come before the base form of the main verb. They are used to express meanings such as possibility, permission, ability, obligation, and intention.

Core Modal Verbs:

• can
• could
• may
• might
• shall
• should
• will
• would
• must

Each of these verbs carries a distinct shade of meaning. For example, can relates to ability, while must signals obligation. Though small in number, these verbs appear across a wide range of sentence types—formal and informal, spoken and written.

Note: Other expressions like ought to, have to, or need to function similarly and are known as semi-modal verbs, which are covered separately in the helping verbs guide.

Uses of Modal Verbs

Each modal verb carries a specific function that changes the tone or intent of a sentence. They don’t describe action, but rather the attitude or likelihood connected to the action. Below are common functions of modal verbs, explained with fresh examples for each.

Expressing Ability or Possibility

Modal verbs like can and could are used to show what someone is able to do, or what might be possible under certain conditions.

• Liam can solve complex puzzles in minutes.
• We could travel next week if schedules allow.

Asking for or Giving Permission

May, can, and might are often used to ask politely or allow something to happen.

• May I borrow your notes for the afternoon?
• You can leave once your section is complete.

Giving Advice or Making Suggestions

Should and shall help express recommendations or soft commands.

• You should revise your draft before submitting.
• Shall we start with the easiest topic first?

Showing Obligation or Necessity

Must and have to indicate rules, requirements, or strong necessity.

• Every employee must complete the safety training.
• We have to submit the form by Friday. (semi-modal)

Talking About Probability or Certainty

Will, would, might, and may show how likely something is to happen.

• They might announce the results by tomorrow.
• She will join us once the meeting begins.

Modal verbs do not work alone—they always support the main verb, and their placement shapes both tone and meaning in a sentence.

Modal Verbs in Questions and Negatives

Modal verbs are often used to form questions and negative statements. Unlike regular helping verbs, modals follow a consistent pattern—they come directly before the subject in questions and directly before not in negatives.

Questions with Modals

To form a question, place the modal at the beginning of the sentence:

• Could you explain that again?
• Should we notify the coordinator in advance?
• May I speak to the manager?

These questions are polite, direct, and grammatically complete with just one modal + the base verb.

Negative Statements with Modals

To create a negative sentence, add not immediately after the modal verb:

• You should not ignore the guidelines.
• They might not arrive before 8 p.m.
• He cannot drive at night.

In spoken and informal writing, contracted forms like can’t, won’t, shouldn’t, and mightn’t are also common.

Unlike do, does, or did, modal verbs do not require an extra helping verb to form questions or negatives—they work independently with the main verb.

Modal Verbs vs. Main Verbs

Modal verbs and main verbs serve different purposes in a sentence. Modal verbs do not express the core action; instead, they modify or support the main verb by showing intent, ability, permission, or certainty.

For example, in the sentence You must attend the session, the verb must is a modal—it adds urgency or obligation to the main action attend. The sentence would still make sense with just attend, but it would lose the sense of necessity.

Main verbs describe what the subject does or experiences. They can appear on their own or with helping verbs. In contrast, modal verbs cannot stand alone—they always require a main verb in its base form.

Modals never change form: they don’t take –s in the third person (she can, not she cans), and they don’t use “to” before the main verb (should go, not should to go). These rules make modals predictable but powerful tools in shaping meaning.

Sequence and Placement of Modal Verbs in Sentences

Modal verbs follow a simple structure in English: they come directly before the base form of the main verb. This rule holds true even when other elements—like adverbs or objects—are present in the sentence.

For example:

• She might already know the answer.
• You should definitely ask before deciding.
• They will probably return by noon.

In each sentence, the modal verb (might, should, will) appears first, followed immediately by the base verb (know, ask, return), with any adverbs placed in between.

Incorrect placement often happens when adverbs or extra phrases are added in the wrong order:

• ❌ She already might know the answer.
• ✅ She might already know the answer.

Modal verbs never take “to” before the main verb (should go, not should to go) and do not change form based on the subject.

This consistency makes them easier to use than many other verb forms, but their placement still requires attention, especially in longer or more complex sentences.

Using Modals in Conditional Sentences

Modal verbs are commonly used in conditional sentences to show outcomes, possibilities, or imagined situations. Depending on the type of condition, different modals are used to reflect time and likelihood.

In real conditionals, modals show what will or can happen if something is true or likely:

• If you leave now, you will catch the last train.
• If she studies consistently, she can improve her scores.

In unreal or hypothetical conditionals, modals like would, could, or might express imagined results:

• If I had more time, I would travel abroad.
• He might join us if he finishes early.
• If they tried harder, they could win the competition.

In each case, the modal verb appears in the result clause, not the “if” clause. This placement helps signal whether the speaker is talking about something likely, possible, or purely imagined.

Modal verbs add flexibility and nuance to conditional sentences, making them useful for everything from polite suggestions to complex hypothetical reasoning.

FAQs About Modal Verbs