Modal verbs and their meanings
Many modals have more than one use, so the context tells you which meaning applies.
| Modal | Main uses | Example |
|---|---|---|
| can | Ability, permission, possibility | I can drive. You can sit here. |
| could | Past ability, polite request, possibility | She could read at four. Could you help me? |
| may | Formal permission, possibility | You may begin. It may rain. |
| might | Weaker possibility | He might be late. |
| must | Strong obligation, logical certainty | You must wear a helmet. She must be home. |
| shall | Offers and suggestions, formal rules | Shall I open the window? |
| should | Advice, expectation | You should rest. It should arrive today. |
| will | Future, promises, offers | I will call you. |
| would | Polite requests, imagined situations | Would you like tea? I would travel more if I could. |
Four grammar rules
Use the base verb after a modal. Write "He can swim", not "He can swims" or "He can to swim".
Modals don't change with the subject. There is no -s: "She must go", not "She musts go".
Questions and negatives don't use do. Write "Can you help?" and "You should not worry", not "Do you can help?"
Use have plus a past participle to talk about the past. "You should have called" means you didn't call. "She may have left" means it is possible that she left.
Modal-like verbs
Have to, ought to, be able to and need to behave partly like modals, but some of them do change with the subject: "She has to work." Must and have to are close in meaning, but their negatives are very different. "You mustn't go" means it is not allowed. "You don't have to go" means it is not necessary.
Common mistakes
Wrong: She can speaks three languages.
Right: She can speak three languages.
A modal is followed by the base verb.
Wrong: You should to see a doctor.
Right: You should see a doctor.
Don't put to after should. Ought to is the exception.
Wrong: I must went there yesterday.
Right: I had to go there yesterday.
Must has no simple past form for obligation. Use had to.
Using this in IELTS and PTE
Modals let you sound careful in IELTS Writing Task 2 and PTE Write Essay. "This may reduce traffic" is a more defensible claim than "This reduces traffic". Might, could and may are useful when you discuss possible effects, and should helps when you recommend a solution.
5 questions
Exercise
Try each one, then open it to check your answer.
1. Correct this: "He cans play the piano."
He can play the piano.
Modals never take -s.
2. Which is stronger advice or obligation: should or must?
Must.
Should gives advice, while must shows strong obligation.
3. Correct this: "Do you can come tonight?"
Can you come tonight?
Modals form questions without do.
4. What does "You don't have to pay" mean?
Payment isn't necessary.
It means there is no obligation. You mustn't pay would mean paying is not allowed.
5. Complete this: "I'm sorry, you ___ have told me earlier." (advice about the past)
should
Should have plus a past participle describes something that didn't happen but was the right thing to do.
Frequently asked questions
How many modal verbs are there?+
Nine are usually listed as core modals: can, could, may, might, must, shall, should, will and would. Ought to, need and dare are sometimes called semi-modals.
What is the difference between may and might?+
Both show possibility. Might often suggests a slightly lower chance, though many speakers use them almost the same way.
Can two modals go together?+
Not in standard English. Instead of "will can", write "will be able to".
Keep going
More grammar lessons
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