This lesson focuses on the needn’t have and can’t have modals. To form, simply combine the negative modal, have, and the past participle.
Form
needn’t or can’t have + past participle
Can’t Have + Past Participle
- Use this when we are definitely sure that something did not happen in the past or we believe that something was impossible in the past.
Her car is still in the garage. She can’t have left the house yet.
He can’t have escaped through this window – it’s too small.
He can’t have been at the meeting. He’s on a business trip this week.
Needn’t Have + Past Participle
- Use this to mean that the action is done, but it was unnecessary and even a waste of time.
Yesterday my friend had already bought two tickets for the concert so you really needn’t have bought another one, it was a waste of money.
Martha worked all the weekend to finish her assignment on time, but actually she needn’t have done so.
The bus arrived two minutes after you left, so you needn’t have taken a taxi.
Needn’t Have and Can’t Have Modals Exercise
Answer this exercise on needn’t and can’t have modals.
1. You _____ cleaned your room. The housekeeping would’ve tidied it up for you.
a. can’t have
b. needn’t have
2. They _____ left the country because their children are still in the middle of their school year.
a. can’t have
b. needn’t have
3. We _____ rehearsed that intensely. The competition is canceled.
a. can’t have
b. needn’t have
4. I didn’t rain so you ______ brought an umbrella.
a. can’t have
b. needn’t have
5. She is very polite. She _____ spoken to her manager in a rude manner.
a. can’t have
b. needn’t have
6. We had a lot of food in the fridge so we _____ gone to the supermarket today.
a. can’t have
b. needn’t have
7. You _____ seen that movie. It isn’t released until next month.
a. can’t have
b. needn’t have
8. You _____ bought all these presents for her. She doesn’t feel like celebrating her birthday this year.
a. can’t have
b. needn’t have
9. I _____ taken this medicine. I’m allergic to it.
a. can’t have
b. needn’t have
10. He ______ seen her in town. She left for the US last month.
a. can’t have
b. needn’t have
Find the answers to this exercise here.
See also: Modals of Deduction and Speculation and Modals: Will, May, Might
For additional information on this topic, check out this BBC Learning English lesson.
For other English grammar lessons, go to this page.