Complete bilingual study notes for Modals (Verbs) — every concept explained step by step, with definitions, formulas, and worked examples.
Modals — Complete Grammar Guide
What are Modal Verbs?
Modal verbs (also called modals) are helping verbs that express ability, possibility, permission, obligation, advice, necessity or future intention. The main modal verbs are: can, could, may, might, will, would, shall, should, must, ought to, need and dare.
Modal verbs are always followed by the base form of the main verb (V1).
Why Do We Use Modal Verbs?
Modal verbs help us express different shades of meaning such as ability, permission, possibility, obligation and advice. In the SEE examination, modals are tested through fill-in-the-blank questions, choosing the correct modal, and rewriting sentences. Correct use of modals improves both accuracy and fluency in English.
- To express ability, permission, possibility and obligation
- To give advice and make suggestions
- To talk about future and past habits
- It is an important grammar topic in Grade 10 SEE English
Important Characteristics of Modal Verbs
- 1Modal verbs do not take -s / -es with he, she or it. (He can swim. Not: He cans swim.)
- 2Modal verbs are followed by the base form of the verb (V1). (She can write. Not: She can writes / writing.)
- 3Most modals do not use “to” before the main verb (except ought to and have to).
- 4Modal verbs form questions and negatives without do/does/did.
- 5Modal verbs have no infinitive or participle forms of their own.
1. Can and Could
Uses of Can
| Use | Example |
|---|
| Ability (present) | She can speak English. |
| Permission (informal) | Can I use your phone? |
| Possibility | It can be true. |
| Request | Can you help me? |
Uses of Could
| Use | Example |
|---|
| Ability in the past | She could swim when she was five. |
| Polite request | Could you open the window, please? |
| Possibility (less certain) | It could rain later. |
| Suggestion | You could try this method. |
Negative and Question Forms
- She cannot (can’t) swim.
- Can she swim?
- He could not (couldn’t) come yesterday.
- Could he come yesterday?
2. May and Might
Uses of May
| Use | Example |
|---|
| Permission (formal) | May I come in? |
| Possibility | It may rain today. |
| Wish / blessing | May you succeed! |
Uses of Might
| Use | Example |
|---|
| Possibility (weaker than may) | It might rain later. |
| Past possibility | He might have missed the bus. |
| Polite suggestion | You might try calling him. |
3. Will and Would
Uses of Will
| Use | Example |
|---|
| Future intention / prediction | I will help you. It will rain tomorrow. |
| Promise | I will never leave you. |
| Willingness | I will carry the bag for you. |
| Request | Will you open the door? |
Uses of Would
| Use | Example |
|---|
| Past habit | When I was a child, I would play in the garden. |
| Polite request | Would you please help me? |
| Hypothetical / imaginary | I would buy a car if I had money. |
| Willingness in the past | He would not listen to me. |
4. Shall and Should
Uses of Shall
| Use | Example |
|---|
| Future with I / We (formal) | I shall return tomorrow. |
| Offer / Suggestion | Shall I open the window? Shall we go for a walk? |
Uses of Should
| Use | Example |
|---|
| Advice / Recommendation | You should study hard. |
| Obligation / Duty | We should respect our parents. |
| Probability | He should be here by now. |
| In conditional sentences | If you should see him, tell him to call me. |
5. Must and Have to
Uses of Must
| Use | Example |
|---|
| Strong obligation / necessity | You must wear a helmet. |
| Strong advice | You must see a doctor. |
| Logical conclusion | He must be tired. (I am sure he is tired.) |
Uses of Have to / Has to / Had to
| Use | Example |
|---|
| External obligation | I have to wear a uniform at school. |
| Past obligation | I had to finish the work yesterday. |
| Future obligation | She will have to leave early tomorrow. |
Must vs Have to
| Must | Have to |
|---|
| Internal obligation or strong personal feeling | External obligation (rules, law, circumstances) |
| You must stop smoking. (I feel it is necessary) | You have to stop here. (It is the rule) |
| Must not = prohibition | Don’t have to = no necessity |
6. Ought to
“Ought to” is similar to “should”. It expresses duty, advice or moral obligation.
- You ought to respect your elders.
- She ought to apologise.
- We ought to help the poor.
Negative: ought not to / oughtn’t to
7. Need (as Modal)
As a modal, “need” is mainly used in negative and question forms.
- You need not come tomorrow. (You don’t have to come.)
- Need I say more?
- He need not worry.
8. Dare (as Modal)
As a modal, “dare” means to have the courage to do something. It is mainly used in negative and question forms.
- How dare you speak to me like that?
- He dare not oppose the decision.
- Dare she enter the room?
9. Used to
“Used to” expresses past habits or situations that are no longer true.
- I used to play football when I was young.
- She used to live in Pokhara.
- There used to be a cinema here.
Negative: did not use to / used not to
Question: Did you use to...?
Important Differences
| Can | Could |
|---|
| Present ability / informal permission | Past ability / polite request / weaker possibility |
| She can swim. | She could swim when she was young. |
| May | Might |
|---|
| Permission / stronger possibility | Weaker possibility |
| It may rain. | It might rain. |
| Must | Have to |
|---|
| Strong personal obligation or logical conclusion | External obligation |
| You must stop smoking. | You have to wear a uniform. |
| Should | Ought to |
|---|
| Advice / mild obligation | Moral duty / advice (slightly stronger) |
| You should study hard. | You ought to respect your parents. |
Important Rules
- 1Modal verbs are always followed by the base form (V1).
- 2Do not add -s / -es to modals with he/she/it.
- 3Most modals do not take “to” (except ought to and have to).
- 4Questions and negatives are formed without do/does/did.
- 5“Must not” means prohibition; “don’t have to” means no necessity.
- 6“Used to” is for past habits that are no longer true.
- 7“Could”, “would”, “might”, “should” can also be used for past or polite meanings.
Common Mistakes
- 1Wrong: She cans swim. Correct: She can swim. Reason: Modals do not take -s.
- 2Wrong: He can to swim. Correct: He can swim. Reason: No “to” after most modals.
- 3Wrong: She must to go. Correct: She must go. Reason: No “to” after must.
- 4Wrong: You should to study. Correct: You should study. Reason: No “to” after should.
- 5Wrong: Did she can come? Correct: Could she come? / Was she able to come? Reason: Use could or be able to for past ability questions.
- 6Wrong: I must to finish it. Correct: I must finish it. / I have to finish it.
- 7Wrong: She used to went there. Correct: She used to go there. Reason: After used to, use V1.
Remember (Memory Tricks)
- Modal + V1 (base form)
- No -s with he/she/it
- can = ability / permission; could = past / polite
- may = permission / possibility; might = weaker possibility
- must = strong obligation; have to = external obligation
- should / ought to = advice
- used to = past habit (no longer true)
- mustn’t = prohibition; don’t have to = not necessary
SEE Exam Tips
- 1Read the sentence carefully to understand the meaning (ability, permission, obligation, advice, possibility, etc.).
- 2Choose the modal that best matches the meaning.
- 3Always use the base form of the verb after the modal.
- 4Check whether the sentence needs present, past or polite form.
- 5Remember the difference between must and have to, can and could, may and might.
- 6In rewriting questions, keep the original meaning the same.
- 7Practise common pairs and their differences regularly.
How Modals Appear in SEE
- Fill in the blanks with suitable modals
- Choose the correct modal from the options
- Rewrite the sentences using the given modal
- Complete the sentences with the correct form
Quick Revision
- Modal + base verb (V1)
- can / could = ability, permission, possibility
- may / might = permission, possibility
- will / would = future, polite request, past habit
- shall / should = offer, advice, duty
- must / have to = obligation
- ought to = moral duty / advice
- used to = past habit
- mustn’t = prohibition; don’t have to = no necessity