Fill in the blanks with must, must not, can or cannot.
1. You have been working all day. You .............................. be tired.
We can use must to talk about a logical possibility.
2. She ......................... be very bored with her job. She does the same thing every day.
3. It .............................. be the postman. He has already been.
Cannot shows certainty.
4. You ................................. be joking.
5. When I saw her, she was crying. She ............................ have a problem.
6. There is no light in his room. He ......................... be asleep.
7. She is new to the city. She ............................ have many friends here.
8. He has been living in this city for well over two decades. He ........................... know a lot of people here.
9. You haven't eaten anything since morning. You ......................... be hungry.
10. You have just had lunch. You .......................... be hungry now.
11. He worked really hard for this promotion. He .............................. be pleased.
12. They live in the same neighborhood. They .............................. know each other.
Answers
1. You have been working all day. You must be tired.
2. She must be very bored with her job. She does the same thing every day.
3. It cannot be the postman. He has already been.
4. You must be joking.
5. When I saw her, she was crying. She must have a problem.
6. There is no light in his room. He must be asleep.
7. She is new to the city. She can’t have many friends here.
8. He has been living in this city for well over two decades. He must know a lot of people here.
9. You haven’t eaten anything since morning. You must be hungry.
10. You have just had lunch. You can’t be hungry now.
11. He worked really hard for this promotion. He must be pleased.
12. They live in the same neighborhood. They must know each other.
