The document discusses the use of various modal verbs like might, may, could, can't, should have, would have, etc. when talking about unreal or hypothetical past situations. It provides examples of sentences using these modal verbs to express possibilities, uncertainties, or imagined alternatives regarding past events. It also includes exercises for the reader to identify which modal verb is being used in different example sentences.

1. By: JhoanM. Tagaban
&
RickaMae Tolentino

3. - Might/May/Could/+Perfect Infinitive
We use might, may or could with the perfect infinitive to say
that we think something was possible but we aren’t sure.
Examples:
The thieves might have escaped by car but we can’t be sure.
He should be hour by now. He may have been delayed by a
traffic jam or something.
I can’t find my purse. I could have left in the supermarket but I
just don’t know.

4. - Might/May/Could/+Perfect Infinitive
We use might, may or could with the perfect infinitive to say
that we think something was possible but we aren’t sure.
Examples:
The thieves might have escaped by car but we can’t be sure.
He should be hour by now. He may have been delayed by a
traffic jam or something.
I can’t find my purse. I could have left in the supermarket but I
just don’t know.

5. - Can’t + perfect infinitive
we use can’t + perfect infinitive when we feel
sure something didn’t happen in the past.
Examples:
I thought I saw John in town this morning but it
-
can’t have been him- he’s in Greece this week.
I can’t have left in the supermarket- I had it on
the bus on the way home.
You can’t have read the instructions properly.
They’re perfectly clear

6. -

7. Should Have
Use should have to say that a different action was
recommended in the past.
Examples:
If you arrive late to English class, you can say:
“I should have left my house earlier.”
If you regret an argument, you can say:“I shouldn’t
have yelled at you yesterday. I’m sorry.”
You can also use should have / shouldn’t have to tell
other people that a different action in the past would
have been better. If your son fails a test, you can say:
“You should have studied. You shouldn’t have played
video games all weekend.”

8. -
Could Have
Use could have to talk about possibilities if
something had been different in the past.
For example, someone who didn’t go to
college can say:
“If I had gone to college, I could have gotten a
better job.”
When talking about a gymnast who didn’t win
a competition, you can say:
“She could have won the gold medal if she
hadn’t fallen three times.”

9. Could have is often used with “if + had + past
participle” (If I had gone / if she hadn’t fallen) –
these “if” phrases express the imaginary past
situation. However, in some cases you can use
-
could have without the “if” phrase. Imagine
you’re driving with a person who makes a
dangerous maneuver on the road. You can say:
“Are you crazy? We could have gotten into an
accident.”

10. Would Have
Use would have to imagine a result (if something
had been different in the past):
If you arrive late at the airport and miss your
flight, you can say:
-
“If we had arrived earlier, we would have caught
our flight.”
If you forget your umbrella, and it starts to rain,
and you get wet, you can say:
“If I had brought my umbrella, I wouldn’t have
gotten wet in the rain.”

11. -
Would have expresses more certainty about
the result than could have:
“If I had worked harder, I could have gotten a
promotion.”
(maybe I’d get a promotion… but maybe not)
On a test where you need 70% to pass:
“I got a 68 on the test. If I had gotten two
more points, I would have passed.”
(with the two points, passing the test is
CERTAIN)

12. EXERCISES
Direction: write if it is must have, might have, should have, can’t have.
1. John ____ gone on holiday. I saw him this morning downtown.
2. Nobody answered the phone at the clinic. It ____ closed early.
3. I ____ revised more for my exams. I think I’ll fail.
4. Sarah looks really pleased with herself. She ____ passed her driving test this
morning.
5. I didn’t know you were going to Phil’s party yesterday. You ___ told me!
6. I can’t believe Jim hasn't arrived yet. He ___ caught the wrong train.
7. I can’t believe Jim hasn't arrived yet. He ___ caught the correct train.
8. His number was buy all night. He ___ been on the phone continuously for hours.
9. It ___ been Mickey I saw at the party. He didn’t recognize me at all.

13. 1. Bill hasn’t arrived for the meeting yet, he ____(get) stuck in traffic. There’s no other
possibility.
2. Sally’s car is still parked outside her house, she ___ (leave) for work yet because she
always goes by car.
3. His phone is out of battery, he ___ (forget) to charge it. I’m certain of it.
4. I'm not sure where my keys have disappeared to, but I suppose I ____ (leave) them on
my desk. It’s certainly a possibility.
5. I'm not surprised you failed the job interview, you ____ (study) more!

14. 6. You__(tell) her that her hair looked bad, she’s going to be upset with all day.
7. There are puddles of water on the pavement, it ____ (rain). It’s the only
explanation
8. You behaved terribly last night, you ___ (drink) so much!
9. Its midnight already! We ____ (spend)the last three hours talking!
10. Its hard to say for certain, but the classical music performance last night ____
(be) the best I've ever heard.

15. -
11. There’s a mosquito in here, it _____ (come)in through the window. No doubt
about it.
12. The government ___ (do) something about the financial situation a long time
ago.
13. I can’t believe that you won the football match, your team is terrible. You ___
(have) a lot of luck.
14. This soup is so thick and tastes so nice! They ___ (put) a lot of cream in it.
15. I know it’s too late to say it now, but I ____ (waste) so much money on silly things
last night.