This third mixed modals exercise practices can, should, and must in natural everyday contexts. The key is identifying what the sentence is really expressing — ability, advice, or logical deduction — and matching that to the right modal. Start with exercise 1 if you haven’t already.
Need a refresher? Review the grammar ↓
READY TO PRACTICE? LET’S GO!
Choose the modal verb that best completes each sentence.
1. You look pretty tired. I think you ________ rest.
Correct answer: should
2. Mary hasn't eaten since this morning. She ________ be very hungry!
Correct answer: must
3. We ________ leave anytime you want.
Correct answer: can
4. ________ you please ask the neighbor to turn down his music?
Correct answer: Can
5. This is a dangerous neighborhood. You ________ be careful here.
Correct answer: should
6. I have to see if I ________ leave my car here overnight.
Correct answer: can
7. Oliver ________ have been so upset that his team lost!
Correct answer: must
8. My father ________ believe that I aced all my exams.
Correct answer: can't
9. William isn't sure if he ________ buy his mom flowers or something else.
Correct answer: should
10. How ________ they afford such an expensive apartment?
Correct answer: can
11. This video looks real, but it might have been made with AI. You ________ check where it came from before sharing it.
Correct answer: should
12. Maya edits all her podcast episodes herself. She ________ know a lot about editing audio!
Correct answer: must
13. I have tried three times, but I still ________ connect to the video meeting.
Correct answer: can't
14. Our streaming plan allows two people to watch at once, so you ________ use your tablet while I watch on the TV.
Correct answer: can
15. You never use that fitness app anymore. I think you ________ cancel the paid subscription.
Correct answer: should
16. ________ you send me the link to your online shop, please?
Correct answer: Can
17. Students ________ complete this online exam without an AI assistant. It's a strict requirement.
Correct answer: must
18. Leo spent six hours making that short video. He ________ have worked really hard on it!
Correct answer: must
19. I know how to repair a flat tire, but I ________ fix the motor on an electric bike.
Correct answer: can't
20. You have posted your home address on your public profile. I think you ________ remove it.
Grammar reviewCan, should and must — choosing the most natural option
This exercise asks you to choose the more natural-sounding modal. That is a different skill from simply knowing the grammar rules — it requires understanding how native speakers actually use these words in everyday conversation.
Context clues that point to must:
When a sentence describes something that is almost certainly true based on evidence or logic: He didn't answer any calls all weekend. He ________ be busy. (logical deduction)
Context clues that point to can:
When a sentence describes what someone is or isn’t able to do: She's fluent in three languages. She ________ switch between them easily.
Context clues that point to should:
When a sentence offers a recommendation, warning, or suggestion: Your eyes are red. You ________ take a break from the screen.
Did you know?
Unlike most English proficiency tests, the Cambridge English Qualifications include a dedicated grammar section called “Use of English.” This appears in the FCE (B2 First), CAE (C1 Advanced), and CPE (C2 Proficiency) exams and tests grammar and vocabulary directly through tasks such as multiple-choice cloze, open cloze, word formation, and sentence transformations. If you’re preparing for a Cambridge exam, targeted grammar practice — including modal verbs — is essential.