Instructions. Type the past progressive form using the verbs in parenthesis. Example: Henry: Sorry I didn't call last night. Paula: You (must, work) _______________ on an important assignment. Henry: Yes. I was at the library until midnight doing research for a paper.
must have been working
Explanation
May have been, might have been, had to have been and could have been, + verb-ing refer to the probability of actions occurring or not occurring over a period of time in the past.
Examples A: Bill wasn't home last night. B: He had to have been working. Speaker B is 100% certain that Bill was working.
A: Bill wasn't home last night. B: He must have been working. Speaker B is almost certain that Bill was working.
May have been, might have been, and could have been have about the same meaning. A: Bill wasn't home last night. B: 1) He may have been working; 2) He might have been working; 3) He could have been working. Responses 1-3 all express the same idea, that there is a fifty-fifty chance that Bill was working.
Student: I didn't know that we were going to have a test today. Professor Dowell: You must not have been listening in class yesterday. Professor Dowell is almost certain that the student was not listening.
Student: I didn't know that we were going to have a test today. Professor Dowell: You could not have been listening in class yesterday. Professor Dowell is 100% certain that the student was not listening.
John: I called Bill last night but he wasn't home. I wanted to borrow his electric drill. Mark: He (could, work) ____________________________ at the shop.
Janet: I saw your sister at the mall yesterday. Clara: She (might, buy) _______________ a birthday gift for my mom. Her birthday is this coming Tuesday.
Son: I don't know how I hit the tree. I just didn't see it. Father: You (must, not, pay) ___________________ much attention when you were backing out.
Motorist1: What a terrible accident! The car hit the semi head on. Motorist 2: This road is only two lanes. The car (must, try) ______________ to pass and he didn't see the truck coming until it was too late.
The driver (had to, drink) ____________. There were five empty beer cans in his car plus an open one that had been partially drunk.
The semi driver (may, go) ________________ over the speed limit but there is no proof of that.
The driver of the car was not thrown from his vehicle, so he (must, wear)_________________ a seat belt.
Mother: Where were you last night? Daughter: We had volleyball practice. Mother: You (could, not, practice) ________________ volleyball all night. Did you go somewhere after practice?