Learn about special helping verbs that show ability, possibility, permission, and obligation. Perfect for Class 6-12 students. Master modal verbs with clear examples and usage rules.
1. What are Modal Verbs?
Modal verbs are special helping verbs that express ability, possibility, permission, or obligation. They help main verbs show different meanings.
| Modal Verb | Main Use | Example | What It Shows |
|---|---|---|---|
| can | Ability/Permission | I can swim. | Present ability |
| could | Past ability/Politeness | I could run fast. | Past ability |
| may | Permission/Possibility | May I come in? | Formal permission |
| might | Weak possibility | It might rain. | Less certain |
| must | Strong obligation | You must study. | Compulsion |
| Key Point: Modal verbs never change form (no -s, -ing, -ed) | |||
2. Common Modal Verbs and Their Uses
| Modal | Uses | Examples | Negative Form |
|---|---|---|---|
| can | Ability, Permission, Request | She can speak French. Can I go out? Can you help me? |
cannot/can't |
| could | Past ability, Polite request, Possibility | I could ride a bike at 5. Could you pass the salt? It could be true. |
could not/couldn't |
| may | Permission, Possibility, Wish | May I leave early? It may snow tonight. May you be happy! |
may not |
| might | Weak possibility, Suggestion | She might come later. You might try this method. |
might not/mightn't |
| must | Obligation, Strong recommendation, Certainty | You must wear a helmet. You must see this film! She must be tired. |
must not/mustn't |
| should | Advice, Expectation, Suggestion | You should exercise. He should be here soon. Should we wait? |
should not/shouldn't |
| would | Polite request, Habit, Conditional | Would you help me? He would always smile. I would go if I could. |
would not/wouldn't |
| will | Future, Promise, Willingness | I will call you. I will help you. Will you marry me? |
will not/won't |
| shall | Formal future, Suggestion, Offer | We shall overcome. Shall we dance? Shall I open the window? |
shall not/shan't |
3. Modal Verbs for Different Functions
| Function | Modal Verbs | Examples | Strength |
|---|---|---|---|
| Ability | can, could, be able to | I can swim. (present) I could swim. (past) I will be able to swim. (future) |
High → Low |
| Permission | can, could, may, might | Can I go? (informal) May I go? (formal) Could I go? (polite) |
Formal → Informal |
| Possibility | may, might, could, can | It may rain. (likely) It might rain. (less likely) It could rain. (possible) |
Strong → Weak |
| Obligation | must, have to, should, ought to | You must stop. (strong) You have to stop. (external) You should stop. (advice) |
Strong → Weak |
| Advice/Suggestion | should, ought to, could, might | You should study. (strong advice) You could try this. (suggestion) You might want to see this. |
Direct → Indirect |
4. Past Forms of Modal Verbs
| Present Modal | Past Form | Usage | Example |
|---|---|---|---|
| can | could/was able to | General ability vs specific achievement | I could swim. (ability) I was able to win. (achieved) |
| may | might/was allowed to | Possibility vs permission | It might rain. (possibility) I was allowed to go. (permission) |
| must | had to | Obligation in past | I must go. (now) I had to go. (past) |
| will | would | Future in past | He will come. (future) He said he would come. (past future) |
| shall | should | Future in past (formal) | We shall win. (future) We thought we should win. |
| Note: Some modals use different phrases for past (be able to, be allowed to, have to) | |||
5. Negative Forms and Their Meanings
| Modal | Negative Form | Meaning | Example |
|---|---|---|---|
| can | cannot/can't | Inability, Impossibility | I can't swim. (unable) It can't be true! (impossible) |
| must | must not/mustn't | Prohibition (strong) | You mustn't smoke here. |
| should | should not/shouldn't | Advice against something | You shouldn't eat junk food. |
| may | may not | Prohibition (formal) or Possibility not | You may not enter. (prohibition) She may not come. (possibility) |
| need | need not/needn't | No necessity | You needn't worry. (not necessary) |
| Important: "must not" ≠ "do not have to" - Mustn't = prohibition, Don't have to = no necessity | |||
6. Quick Practice (5 Questions)
7. Common Mistakes to Avoid
| Wrong ❌ | Right ✅ | Why? |
|---|---|---|
| I can to swim. | I can swim. | Modal + base verb (no "to") |
| He cans speak English. | He can speak English. | Modals don't add -s for he/she/it |
| I must to go now. | I must go now. | Modal + base verb (no "to") |
| She didn't can come. | She couldn't come. | Modals don't use "do" for negative |
| You must not to smoke. | You must not smoke. | Modal + not + base verb (no "to") |
| I will can help you. | I will be able to help you. | No double modals (can't use two together) |
🎯 Modal Verb Quiz
Choose the correct modal for each situation:
1. Asking permission politely:
A) Can I borrow your pen?
B) May I borrow your pen?
C) Both are correct
2. Showing past ability:
A) I can play guitar at age 10.
B) I could play guitar at age 10.
C) I might play guitar at age 10.
3. Strong advice to a friend:
A) You could exercise more.
B) You should exercise more.
C) You might exercise more.
Answers: 1-C, 2-B, 3-B
8. Memory Aids & Tips
Modal Verb Rules:
1. No -s in third person (He can, not He cans)
2. No "to" after modal (can go, not can to go)
3. No -ing or -ed forms
4. Followed by base verb (can eat, not can eating)
5. No double modals (❌ will can, ✅ will be able to)
Polite Requests Scale:
Can you...? (informal)
Could you...? (polite)
Would you...? (more polite)
Would you mind...? (very polite)
Use "could" and "would" for better manners!
Possibility Scale:
will (100% sure) → must (90%) → should (80%) → may (50%) → might (30%) → could (20%)
Example: It will rain. (certain) vs It might rain. (maybe)
Exam Tip:
1. Check context: Ability? Permission? Obligation?
2. Check tense: Present or past?
3. Check politeness level
4. Remember: No -s, no -ing, no "to" after modals
5. "Must" for obligation, "have to" for external rules
📝 Practice Modal Verbs
Test with our 25-question worksheet on modal verbs!
Download Modal Verbs WorksheetIncludes answer key • All modals • Polite forms • Printable PDF
