Modal Verbs
Express ability, permission, advice, obligation and possibility with can, must, should and more.
What Is It?
Modal verbs (can, could, may, might, must, shall, should, will, would) add meaning to the main verb: ability, permission, obligation, advice or possibility.
Why Do English Speakers Use It?
They let you be polite, give advice, make guesses and set rules, often with just one word.
When to Use It
- Ability: I can swim. She could read at four.
- Permission and requests: Can I sit here? Could you help me?
- Advice: You should drink more water.
- Obligation: You must wear a helmet.
- Possibility: It might rain later.
When NOT to Use It
Don’t add -s, “to” or another modal: “She can drive”, not “She cans drive” or “She can to drive”. Use “will be able to” for future ability.
Sentence Structure
| Form | Pattern | Example |
|---|---|---|
| Positive | modal + base verb | You should go. |
| Negative | modal + not + base verb | You shouldn’t go. |
| Question | modal + subject + base verb? | Should I go? |
Grammar Rules
- Modals never change form: I can, she can.
- Always followed by the base verb without “to” (except ought to).
- Mustn’t = not allowed. Don’t have to = not necessary.
- Could, would, may sound more polite than can or will.
- For deductions: must (almost sure), might/may/could (possible), can’t (impossible).
Real-Life Examples
- Could you open the window, please?
- You mustn’t use your phone during the exam.
- Joe might be late. The traffic is bad.
- She can’t be at home. Her car isn’t here.
Common Learner Mistakes
- He cans speak French.He can speak French.
- You should to study.You should study.
- I will can come tomorrow.I will be able to come tomorrow.
Quick Memory Tip
Modal + bare verb. Nothing in between: no “to”, no -s, no -ing.
Real Conversation
Monica: I have a terrible headache.
Joe: You should lie down. Can I get you some water?
Monica: Yes, please. I might take a painkiller too.
Interactive Practice
Pick an answer to check your understanding.
Question 1 of 5
You ___ smoke here. It’s against the rules.
Question 2 of 5
You ___ wear a seatbelt. It’s the law.
Question 3 of 5
You ___ bring food. There’s plenty here.
Question 4 of 5
It’s hot in here. ___ I open the window?
Question 5 of 5
Her car is outside, so she ___ be at home.
Final Mini Quiz
One last check before you mark the lesson complete.
Which is the most polite request?
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