Fill in the blanks with an appropriate auxiliary verb.
1. The doctor said that I ………………………. exercise. (absolute necessity)
We use must to express absolute necessity.
2. You …………………………. work tomorrow. (lack of necessity)
We use need not to express the lack of necessity.
3. That curtain ………………………… be washed. (absolute necessity)
We use must to express absolute necessity.
4. I …………………………… to walk three miles to school when I was a child. (past necessity)
We use had to to talk about past necessity.
5. You ……………………… get a job. (strong necessity)
We use must to indicate strong necessity.
6. ………………………. I borrow your car? (permission)
7. You can but you …………………………… bring it back by evening. (instruction for future)
8. He said he ………………………… be here at three.
9. She ………………………… have a problem. She is crying. (strong probability)
10. She ………………………. be Jane’s sister. She looks just like her. (certainty)
11. ‘There is the doorbell.’ ‘Who ……………………… it be?’ (conclusion)
We can use can to express conclusion in questions and negatives.
12. ………………………….. I carry this bag? (Necessity)
Answers
1. The doctor said that I must exercise.
2. You need not work tomorrow.
3. That curtain must be washed.
4. I had to walk three miles to school when I was a child.
5. You must get a job.
6. Can I borrow your car?
7. You can but you must bring it back by evening.
8. He said he would be here at three.
9. She must have a problem. She is crying.
10. She must be Jane’s sister. She looks just like her.
11. ‘There is the doorbell.’ ‘Who can it be?’
12. Should I carry this bag?
