Past Modals of Deduction

A: Hey, look at these photos of our great-grandmother that I found in the attic!

B: Wow, she was so gorgeous! She _____________________ very popular with the guys!

• must have been

• couldn't have been

• can have been

I’m not sure, but I think Giovanna ____________ have broken up with her boyfriend. She didn’t bring him for the Christmas’ dinner, after all. What do you think?

• may

• can't

• must

Robert _______________ Mrs. Cruz! Mrs. Cruz was murdered four days ago at around 9 PM, and Robert was in my house all night on that day. I even have videos to prove it! He’s innocent!

• can't have killed

• must have killed

• may have killed

I had the opportunity to study medicine in a prestigious university but I decided to follow my passion and become an actress instead. Imagine that, I _____________________________ a doctor.

• could have become

• must have become

• can't have become

A: I think I saw Nicholas at the mall yesterday.

B: That’s impossible. You _____________________________ Nicholas! He has been in hospital since last week.

• can't have seen

• must have seen

• mustn't have seen

Alexandra applied for Harvard University and she received the results in the morning. She hasn’t said anything yet but she’s extremely happy right now.

• She must have passed the exam.

• She must have failed the exam.

• She can't have passed the exam.

I can’t remember very well but I think I watched this movie some years ago. The characters and the story seem familiar but I’m not completely sure.

• I may have watched this movie.

• I must have watched this movie.

• I can't have watched this movie.

A: Did you see our neighbours' new cars?

B: Yeah! They _________________ the lottery!

• must have won

• could have won

• can have won

Oh no! Where are my keys? I know! I ________ have left them on my office’s desk! This is the fifth time this month!

• must

• might

• could

A: Look at this! I passed the exam without studying!

B: Really? That exam ________ have been difficult then!

• can't

• must

• might