39013 past modal verbs

Past Modal Verbs
Level: 6
Introduction Activity
When we want to use modals to talk about ability, obligation, and
intention in the past, we use a simple word change.
I can play the piano  I could play the piano when I was a kid.
I have to do my homework  I had to do my homework yesterday.
Mark will hand in the report tomorrow.  Mark said he would hand
in the report tomorrow.
Which sentence example is past ability? Past obligation? Past
intention?
When we want to make deductions or speculate about the past, give
an opinion about the past, or express a regret, past modals come in
the form of:
modal + have + past participle
Deductions about the past:
Must have

may have

might have

can’t have

couldn’t have

1. “Sarah isn’t home right now. She must have gone out.”
(Speaker is completely certain that something is true).
2. “Sarah isn’t home right now. She may have gone to the grocery store.”
“Sarah’s not answering her phone. She might have gone out.”
(Speaker is not certain, but it’s possible).

3. “Sarah was in Hawaii when the crime was committed. She can’t have done it.”
(Speaker is completely certain something is not true.)
Giving an opinion or expressing regret about the past:
Should have

shouldn’t have


4. Lisa didn’t get the job because she came to the interview late. She should
have arrived on time.”
(Expressing an opinion)
5. I gained a lot of weight over Christmas. I shouldn’t have eaten so much.
(Expressing a regret)
Discussion: What should banks have done before the wake of the financial
crisis?

Practice Activity 1
Select the correct answer:
1. When Jillian came home, her window was broken and her

2.

3.

4.

5.

computer was missing. Her house _______ burgled.
a. must have been b. couldn’t have been c. has to be

Sarah is very angry with her boyfriend. He ________ done
something wrong.
a. can’t have b. might not have
c. may have d. had to
I noticed when I got to work that I did not have my cellphone. I
________ left it on the bus.
a. must not have b. should have c. couldn’t have
When I arrived in New York City, I realized I had no idea where my
hotel was. I got lost for hours! I __________ brought a map.
a. couldn’t have b. should have c. might have d. must have
My mother has problems with her lungs. She _________ smoked
those cigarettes last night.
a. shouldn’t have b. should have c. must have d. might not
have


Communication Activity 1
With a partner, use past modal verbs to make deductions about the
pictures below:

Communication Activity 2
With a partner, read the following brainteasers. Use past modal verbs to
explain each situation. Try to come up with as many explanations as
possible. Then compare your answers with your classmates’ answers.
1. A man lived on the fourteenth floor of a building. Ever day he took

the elevator to the ground floor to go to work. When he returned,
he took the elevator to the tenth floor and walked up the stairs to
his apartment on the fourteenth floor. He hated walking, so why
did he do it?

2. A man and his son were in a car accident. The man died on the
way to the hospital, but the boy was taken into surgery. The


surgeon said, “I can’t operate, that’s my son!” How was this
possible?
Teacher Explanations:
1. The man was too short to reach any buttons higher than the

button for the 10th floor. (Possible student answers: “The man
must have been too short to reach the other buttons.” “The 11-14
buttons must have been broken.”)
2. The surgeon was his mother. (Possible student answers: “The
surgeon must have been his mother.” “The surgeon may have
been his stepfather.”)