Verbs
Modal Verbs: List, Examples, Rules & Practice
Modal verbs help you express ability, permission, possibility, advice, obligation and willingness. Compare I can leave, I should leave and I must leave: the action stays the same, but the speaker’s meaning changes. This guide gives you the nine central modals, sentence patterns and a practice set with explanations.
Updated September 7, 2026 by the TypoGrammar Editorial Team.
The nine central modal verbs: list and examples
A modal can have more than one use. Read the situation and the rest of the sentence before deciding what it means. For example, must can give a rule or express a confident deduction.
| Modal | Common uses | Example |
|---|---|---|
| can | Ability; permission; general possibility | I can repair the chair. / You can use this desk. |
| could | Past general ability; polite requests; possibility | At ten, I could swim. / Could you move your bag? |
| may | Possibility; formal permission | The delivery may arrive today. / May I sit here? |
| might | Possibility; tentative suggestions | We might try the earlier train. |
| must | Strong obligation; confident deduction | Visitors must sign in. / The lights are on; someone must be home. |
| shall | Offers and suggestions, especially with I or we | Shall I carry that box? |
| should | Advice; expectation | You should save a copy. / The parcel should arrive soon. |
| will | Predictions; willingness; promises | I will send the notes this evening. |
| would | Hypothetical situations; polite offers; repeated past actions | I would cycle if the road were safer. / Would you like some water? |
How to form a sentence with a modal
| Sentence type | Pattern | Example |
|---|---|---|
| Statement | subject + modal + base verb | Maya can speak Spanish. |
| Negative | subject + modal + not + base verb | Maya cannot attend today. |
| Question | modal + subject + base verb? | Can Maya attend tomorrow? |
| Short answer | subject + modal | Yes, she can. / No, she cannot. |
Do not add third-person -s to a modal: She can help, not she cans help. Do not add do to make an ordinary modal question: Could they help?, not Do they could help? The nine modals above take a base verb without to. Related expressions have their own patterns: ought to go, has to go and is able to go.
Three differences that change the meaning
Must not versus do not have to
You must not enter prohibits entry. You do not have to enter makes entry optional. These are not interchangeable negatives. Imagine an optional meeting in a restricted room: you do not have to attend the meeting, and you must not enter the room without permission.
May, might and could: possibility without fixed percentages
The train may be late, might be late and could be late all present lateness as possible. Tone and context can make an expression more tentative, but there is no universal percentage attached to each word. For a confident deduction use must; for something you consider impossible use cannot. Neither deduction is the same as directly observing the fact.
Can, could and was able to
Use can for present ability and could for general past ability: I could read a map when I was nine. To report one successful action, was able to is often clearer: Despite the fog, we were able to find the cabin. A polite question with could can refer to now: Could you check this address?
Past and continuous meanings
For a deduction about the past, use modal + have + past participle: They might have missed the bus. For an action in progress, use modal + be + -ing: They might be waiting outside. You should have saved the file usually looks back at an action that would have been better; it is different from present advice, You should save the file.
Avoid stacking two central modals in standard written English. Instead of I will can join, write I will be able to join. For past obligation, use had to: We had to leave early. Choose the form that matches your intended time and meaning.
Six modal verb exercises with answers
Correct the sentence: She cans explain the route.
Show answer and explanation
She can explain the route. A central modal does not take third-person -s.
Choose the meaning: You must not park here. Is parking forbidden or optional?
Show answer and explanation
Parking is forbidden. You do not have to park here would mean that parking is optional.
You are unsure why Ali is absent. Complete: He ___ be on another call.
Show answer and explanation
May, might or could all work. Each expresses a possibility rather than a confirmed fact.
Correct the question: Do you could send the receipt?
Show answer and explanation
Could you send the receipt? Put the modal before the subject; do not add do.
Rewrite for past obligation: Yesterday we must finish before six.
Show answer and explanation
Yesterday we had to finish before six. Had to expresses the past obligation.
Correct the sentence: I will can attend next week.
Show answer and explanation
I will be able to attend next week. Use be able to after will instead of combining will and can.
Continue practising
Use conditionals to practise would and could in hypothetical situations. Review past simple questions to compare did with modal questions, or try the verb tenses quiz.
References: British Council modal verbs reference and deductions about the present. Examples and exercises are written for this guide.
Apply what you learned
Compare: You must not leave, and You do not have to leave. Do they mean the same thing?
Show answer and explanation
No. Must not prohibits leaving; do not have to means leaving is unnecessary.
Choose the form according to the intended rule. Confusing prohibition with absence of obligation reverses the practical message.