Modal verbs add meaning such as obligation, permission, ability and certainty. This quiz tests the most common ones, with a short explanation after every answer.
1. You ___ wear a seatbelt. It’s the law.
“Must “expresses strong obligation, such as a legal rule.
2. ___ I borrow your pen?
“May I…?”is a polite way to ask permission. “Can I…?”is also common and less formal.
3. She ___ be at home. Her lights are on.
“Must “can express a strong logical deduction: she must be at home.
4. He ___ be the thief. He was abroad at the time.
“Can ‘t “expresses a strong deduction that something is impossible.
5. You ___ pay for the ticket. It ‘s free.
“Don ‘t have to “means there is no obligation.
6. You ___ smoke here. It ‘s prohibited.
“Mustn ‘t “expresses prohibition. It is not the same as “don ‘t have to “.
7. When I was a child, I ___ swim very well.
“Could “describes a general ability in the past.
8. Which sentence is correct?
Modal verbs are followed by the base verb with no “to “and take no -s ending.
9. ___ you help me with this?
“Could you…?”is a polite request.
10. If you want to pass, you ___ study harder.
“Had better “gives strong advice or a warning: you had better study harder.
Frequently asked questions
What is the difference between must and have to?
Must often expresses the speaker’s own sense of obligation or a strong rule. Have to describes an external requirement. In questions and past forms, have to is used because must has no past form.
What is the difference between mustn’t and don’t have to?
Mustn’t means it is prohibited. Don’t have to means it is not necessary. You mustn ‘t smoke here, but you don ‘t have to come early.
What is the difference between can, could and may for permission?
May is the most formal, could is polite, and can is the most common in everyday speech.
