Must have and might have

“They must have known someone was interested in (the property)”

Present Past

It’s (almost) certain …
… that he knows.	... that he knew.
He must know.	He must have known.
It’s possible …
…that he knows.	… that he knew.
He might (may) know	He might (may) have known

Exercise 18. Make sentences with might have or must have.

Where’s Bill?

1. He probably forgot our appointment.

2. Maybe he thought it was for tomorrow.

3. But I’m sure someone told him.

4. He definitely got the message.

5. But it’s possible he didn’t.

6. I probably told him the wrong time.

7. Maybe he misunderstood.

8. It’s very likely he came this morning.

Exercise 19. Complete the following sentences using might have been or must have been.

Example: (delay)

Ken was supposed to be here an hour ago. His train must have been delayed.

1.	(transfer) I’m not sure whether Sandra still works in this department. She ____.
	(deliver) We sent that package two weeks ago, and it only takes four days to get there. It ____ by now.
	(change) I thought the express left at 5.50, but the conductor told me it leaves at 6.15. The schedule ____ since I last took that train.
	(fill) The job opening was announced only yesterday, but it ____ since that time.

Exercise 20. Complete the following sentences using might, might have, must or must have.

	(rain) The roads are all wet; it _____ last night.
	(come) He wasn’t sure, but he said he _____ .
	(misunderstand) He didn’t mean to say that. I _____ him.
	(call) I don’t know whether Joe has called yet. I’ve been out of the office for an hour; he _____ during that time.
	(rain) Let’s go out. But don’t forget your raincoat; it _____ .
	(earn) Mr. Carlson is president of a large corporation; he _____ a high salary.
	(learn) Tom’s been studying music for ten years; he _____ a lot by now.
	(take) You’d better leave early; the trip _____ longer than you think.

Could have and should have

“… with year end less than five months away, it couldn’t have happened at a better time”

Present

Bill doesn’t arrive on time. but…
… he’s able to. (if he wants)	… he’s supposed to.
He could arrive on time.	He should arrive on time.

Past

Bill didn’t arrive on time. but …
…he would have been able to (if he had wanted)	… he was supposed to.
He could have arrived on time.	He should have arrived on time

Exercise 21. Make sentences with could have or should have.

Example: You didn’t call (You had lots of time)

You could have called.

You didn’t call. (You were supposed to.)

You should have called.

	He didn’t buy the car. (He had enough money.)
	He took the money. (He knew it wasn’t his.)
	You didn’t have an accident. (You almost did.)
	We didn’t wait until noon. (We had promised we would.)
	They didn’t get here on time. (It would have been impossible.)
	I didn’t mail the letter. (It was urgent.)
	She stayed home from work. (She wasn’t really sick.)
	We didn’t take the plane. (There are direct flights between here and there.)
	He didn’t get the job. (But he came very close.)
	I didn’t do my homework. (I knew I was supposed to.)

Exercise 22. Complete the following sentences using should be, should have been, could be or could have been.

Example: (pay)

Bills should be paid on time.

	(type) All business letters _____ .
	(hurt) Your accident was serious; you _____ very badly.
	(replace) Our old equipment has caused many maintenance problems; it ____ years ago.
	(lower) There have been too many accidents on that road; the speed limit _____ right away.
	(prevent) If we had discovered the problem sooner, it _____ .
	(repair) This typewriter _____ , but it would be better to buy a new one.
	(send) It took much too long to ship these goods; they _____ earlier.

TEXT № 5