What Is a Modal Verb? Definition, 9 Examples & List

Modal verbs are the “secret helpers” of English grammar—tiny words that change everything about a sentence by telling us if something is possible, allowed, or required. The nine core modal verbs (can, could, may, might, must, shall, should, will, would) never change form, making them surprisingly easy to master. This guide breaks down what modal verbs are, why they matter, and how to teach them in a way that sticks.

Core modal verbs: 9 primary (can, could, may, might, shall, should, will, would, must) · Key functions: ability, permission, possibility, obligation · Educational sources: BBC Bitesize, SJSU, Grammarly · Target audience: KS2 kids to adults

These key facts establish the baseline for understanding modal verbs across educational contexts.

What Is an Example of a Modal Verb?

Modal verbs appear constantly in everyday speech and writing. According to Grammarly (grammar authority), these helpers show possibility, intent, ability, or necessity. The core nine—can, could, may, might, must, shall, should, will, would—each do slightly different jobs.

Simple Sentences with Can

• Ability: She can play the piano. (Twinkl)
• Permission: Can you come to play today?
• Possibility: I can call you later.

Examples Using Must and Should

• Obligation: You must finish your homework. (Twinkl)
• Advice: You should eat your vegetables. (SJSU Writing Center)
• Suggestion: We ought to recycle our waste. (Twinkl)

Negative and Question Forms

Forming negatives and questions with modal verbs is straightforward—simply add “not” or move the modal to the front. From YouTube – Modal Verbs for Kids (English teacher Maci), negative forms include “can’t,” “couldn’t,” “shouldn’t,” and “mustn’t.” For questions: “Can I go to the park?” or “Must we leave now?”

The pattern here is consistent: modal verbs never change, so forming negatives and questions depends on the modal itself, not conjugation rules.

The implication: once students learn the nine core modals, they can form virtually any negative or question using the same predictable rules.

“Modal verbs are very easy to use because they never change form. No s, no ing, no ed.” — Maci, English for Kids Teacher

What Are the Common Modal Verbs?

Grammar references agree on the nine core modal verbs, though extended lists vary. The Grammarly blog lists frequently used modals as: can, may, might, could, should, would, will, must. SJSU Writing Center confirms these express possibility, ability, necessity, and permission.

The 9 Core Modal Verbs

• can — ability, permission, requests
• could — past ability, polite requests
• may — permission, possibility (formal)
• might — possibility (weaker than may)
• must — strong obligation
• shall — formal suggestion or future
• should — advice, recommendation
• will — future, promise
• would — hypothetical, past habits

Semi-Modal Verbs Like Ought To

Beyond the core nine, sources include semi-modals that behave similarly but sometimes require “to.” Per EuroKids (kids education resource), these include “ought to” for mild obligation and “have to” for necessity. LearnLink notes “need to” as another semi-modal variant.

Extended Lists: 13 or 24 Variants

Some educational materials expand to 13 or 24 modal-related verbs when counting phrasal modals and marginal variants. However, the nine core verbs cover virtually all everyday usage for both children and adults. The Onestopenglish (ELT teaching platform) focuses on the main nine for classroom efficiency.

The implication: students who master the nine core modals can handle the vast majority of modal expressions in real communication—extended lists are academic curiosities rather than practical necessities.

“Modal verbs show possibility, intent, ability, or necessity.” — Grammarly, Grammar Authority

How Do You Explain a Modal Verb to a Child?

Children as young as KS2 age encounter modal verbs in reading and writing. British Council LearnEnglish Kids (UK language learning authority) explains that modal verbs show possibility, ability, permission, or obligation. The key is connecting abstract grammar to concrete scenarios kids experience daily.

Simple Definition for KS2

The Teachwire (KS2 teaching resource) defines modal verbs as “secret helpers” that change a sentence’s meaning without changing themselves. Think of them as superhero powers for verbs: “can” gives the ability to do something, “must” means you have to do it, and “should” gives friendly advice.

Everyday Examples Kids Understand

• “Can I go outside?” (asking permission)
• “Should we share our toys?” (making a suggestion)
• “You must brush your teeth” (a rule from parents)
• “It might rain later” (thinking about possibilities)
• “I could jump very high when I was little” (British Council LearnEnglish Kids)

Visual Aids from Twinkl

Twinkl Blog (educational resource platform) recommends worksheets where children categorize modal verbs by what they express: green for ability, blue for permission, red for obligation. Color-coding helps younger learners visually distinguish functions without overwhelming terminology.

What this means: kids grasp modal verbs fastest when the grammar maps onto situations they recognize—asking for help, following rules, or wondering about the future.

What Is a Modal Verb?

Modal verbs belong to a larger family called auxiliary verbs, which “help out” main verbs in a sentence. Universal Class (ESL teaching resource) confirms that modal verbs are used with another verb and never stand alone. Unlike regular verbs, they stay fixed—they never add -s, -ing, or -ed endings.

Definition from Grammar Sources

Grammarly (grammar authority) defines modal verbs as words that express “hypothetical conditions like capability or requests.” They sit directly before the main verb and add layers of meaning—what’s possible, what might happen, what someone is allowed to do, or what must happen next.

Functions: Ability, Permission, Obligation

• Ability: I can swim / She could play piano
• Permission: May I leave early?
• Obligation: You must finish your work tonight (SJSU Writing Center)
• Possibility: It might rain later
• Advice: You should see a doctor (SJSU Writing Center)

Differences from Auxiliary Verbs

All modal verbs are auxiliary verbs, but not all auxiliary verbs are modal. The Twinkl teaching wiki clarifies that auxiliary verbs like “be,” “have,” and “do” help form tenses or questions, while modal verbs specifically add meaning about possibility, necessity, or permission. This distinction matters when children classify verbs in grammar exercises.

The catch: children sometimes confuse modals with main verbs that look similar. “Want” and “like” are NOT modal verbs, even though they sit near the beginning of sentences. Only the nine core modals (plus recognized semi-modals) carry this specific grammatical function.

“You must finish the work tonight.” — EuroKids, Kids Education Blog

How to Teach Modal Verbs in a Fun Way?

Classroom activities bring abstract grammar to life. Onestopenglish (ELT teaching platform) offers ready-to-use exercises for advice scenarios, while Teachwire compiles KS2-specific games and charades activities that get students moving.

Games and Activities

• Modal verb charades: Kids act out scenarios like “You must find your key!” or “Can you pass the ball?” while classmates guess the modal (Teachwire)
• Modal verb bingo: Students match spoken sentences to written modal verb cards
• Role-play permission: Pairs practice “May I…?” and “Can I…?” in realistic social scenarios

Tips from Onestopenglish

The Onestopenglish teaching guide suggests building a “modal verb wall” where students add examples throughout the week. Seeing real-world uses—song lyrics, story quotes, signs—normalizes modals as practical tools rather than isolated grammar points.

Visuals and Songs for Kids

FirstCry (kids education resource) recommends pairing visual charts with brief songs or chants that repeat modal verbs in memorable rhythms. YouTube educational videos use animated characters and repetition to reinforce the nine core modals.

Why this matters: kinesthetic and auditory activities engage learners who struggle with purely textual grammar explanation, and repeated exposure through games solidifies retention better than passive reading.

Related reading: What Is a Polygon? Definition, Types & Examples · The Seven Deadly Sins: List, Order, Meanings Explained

Building on verb definition and examples, modal verbs like can and must express necessity, ability, and permission in sentences.

Frequently Asked Questions

For students and parents navigating English grammar homework, the takeaway is clear: master the nine core modal verbs, recognize that they never change form, and practice them in everyday conversations. For teachers, interactive activities like charades and role-play make these abstract helpers concrete and memorable.