Modal Verbs — can, can't, must, mustn't

A1 Beginner · Lesson 3
CAN

Use can to talk about ability — things you are able to do.

+Cats can see in the dark.
+He can lift very heavy weights.
✏️ Form: subject + can + verb (base form)
⚠️ No –s with he/she/it: "She can cook." ✓   "She cans cook." ✗
CAN'T

Use can't to talk about inability — things you are not able to do.

–I can't reach the top shelf.
–They can't come tonight — they're busy.
✏️ Form: subject + can't + verb (base form)
MUST

Use must for rules and obligations — things that are required.

+You must pay for your ticket before boarding.
+Players must follow the referee's decision.
✏️ Form: subject + must + verb (base form)
MUSTN'T

Use mustn't for prohibition — things that are not allowed.

–You mustn't swim in this area — it's dangerous.
–Students mustn't share their passwords.
✏️ Form: subject + mustn't + verb (base form)

Quick Summary

ModalMeaningExample
canabilityBirds can fly.
can'tinabilityFish can't walk.
mustobligation / ruleYou must queue here.
mustn'tprohibitionYou mustn't speed.

Exercise 1 — True or False?

Read each statement. Choose True or False.

Exercise 2 — Multiple Choice

Choose the correct modal verb to complete each sentence.

Exercise 3 — Matching

Match each sentence to the correct meaning.

Exercise 4 — Gap Fill

Choose the correct modal verb from the dropdown to complete each sentence.

Exercise 5 — Word Order

Click the words to build the sentence in the correct order. Click a placed word to remove it.

Exercise 6 — Word Sort

Click a category box first, then click the sentence to place it there. Click a placed sentence to remove it.

✅ Ability

❌ Inability

📋 Obligation

🚫 Prohibition

Exercise 7 — Complete the Conversation

Choose the correct modal verb to complete the conversation.

🏆 Your Scores

Exercise 1 — True / False–
Exercise 2 — Multiple Choice–
Exercise 3 — Matching–
Exercise 4 — Gap Fill–
Exercise 5 — Word Order–
Exercise 6 — Word Sort–
Exercise 7 — Conversation–