📖 Quick Grammar Reference: Modal Verbs
| Meaning | Modal | Example |
|---|---|---|
| Ability | can / could | She can swim very well. |
| Obligation | must / have to | You have to wear a seatbelt. |
| Advice | should / had better | You should see a doctor. |
| Possibility | might / may | She might be at home. |
| Deduction | must / can’t | He must be tired after that journey. |
Exercise 1 — Fill in the Blank (Complete each sentence with the modal verb in brackets.)
- She (can) swim very well.
- When I was young, I (could) run very fast.
- You (have to) wear a seatbelt in the car.
- I (must) call my mother today.
- You (should) see a doctor about that cough.
- (may) I use your phone, please?
- She (might) be at home now.
- He (must) be tired after that long journey.
- You (had better) leave now, or you will miss the bus.
- They (can't) be serious about that plan!
Exercise 2 — True or False (Read each statement about modal verb rules and circle T (True) or F (False).)
-
Modal verbs add -s in the third person singular (she cans).
T F
-
Modal verbs are always followed by a bare infinitive without to.
T F
-
Must and have to always mean exactly the same thing.
T F
-
Might expresses a lower probability than may.
T F
-
Could is used for a specific successful past achievement in the positive.
T F
Print version: write T or F on the line next to each statement.
Exercise 3 — Write Your Own Sentences (Write 5 sentences using modal verbs.)
- Write a sentence about something you can do well.
- Write a sentence giving someone advice using "should".
- Write a sentence about a rule or obligation using "have to".
- Write a sentence speculating about where a friend might be right now.
- Write a sentence about something you could or couldn't do as a child.
📋 Show Answer Key
Exercise 1
- can
- could
- have to
- must
- should
- May
- might
- must
- had better
- can’t
Exercise 2
- False — modals never add -s: she can (NOT she cans)
- True — she can swim (NOT she can to swim)
- False — must = internal obligation; have to = external obligation/rule
- True — may = fairly likely; might = less likely
- False — use "was/were able to" for a specific past achievement, not "could"
Exercise 3
Open answers. Check that students use the correct modal form: bare infinitive after the modal (no "to"), no third-person -s, and the modal that matches the intended meaning (ability, advice, obligation, possibility).
Modal Verbs Worksheet — FAQ
What does this modal verbs worksheet cover?
This worksheet covers the main modal verbs — can, could, must, should, might, may and had better — used for ability, permission, obligation, advice and possibility. It includes fill-in-the-blank, true/false, and sentence-writing exercises.
What level is this modal verbs worksheet?
This worksheet is designed for B1 (Intermediate) learners who are practising the meanings and forms of English modal verbs.
How do modal verbs behave grammatically?
Modal verbs never add -s in the third person (she can, NOT she cans), they are always followed by a bare infinitive without to (she can swim, NOT she can to swim), and they have no -ing or past participle form of their own.
What is the difference between 'must' and 'have to'?
'Must' expresses internal obligation — the speaker's own decision or feeling: I must call my mother. 'Have to' expresses external obligation — a rule or requirement: You have to wear a seatbelt.
What is the difference between 'may' and 'might'?
Both express possibility, but 'may' implies a higher probability while 'might' suggests a lower probability. 'May' is also the formal modal for permission: May I use your phone?
Can I save this worksheet as a PDF?
Yes. Click the orange ‘Print / Save as PDF’ button at the top of the page. In your browser’s print dialogue, select ‘Save as PDF’ as the destination. The worksheet is formatted for A4 paper.
Is the answer key included?
Yes. Scroll to the bottom of the worksheet to find the collapsible answer key. Click ‘Show Answer Key’ to reveal all answers. If you want to print the answers too, open the key before clicking Print.
What online exercise goes with this worksheet?
The related online exercise is True or False at lexfizz.com/exercises/true-or-false/ — it provides immediate feedback for deciding whether modal verb usage is correct or incorrect.
How is advice expressed with modal verbs?
Should is the most common advice modal (You should see a doctor), ought to is slightly more formal, and had better is stronger, implying a negative consequence if the advice is ignored (You had better leave now, or you will miss the bus).
How long does this worksheet take to complete?
The three exercises take approximately 20–25 minutes for most B1 learners. Allow extra time for the writing task in Exercise 3 if students need to think carefully about forming original sentences.