Perfect Modals B1.3

Past Modals

Escaped Criminal

​What are modals?

They are auxiliary verbs that provide additional and specific meaning to the main verb of the sentence, like showing moods and tenses.

Perfect Modals

Modal verbs are often used to discuss present or future actions, but we use ‘perfect modals’ to talk about actions, events or possibilities in the past. A ‘perfect modal’ is a modal verb combined with a present perfect verb form. We often speak about the past, and we often need to speak about the past in order to explain mistakes or guess about possibilities.

​Can’t have done
Might have done
Needn’t have done

​Would have done
Could have done
Should have done
Must have done

Would / Wouldn’t have + past participle

• We use this form to explain that our choice of action would be different to an action performed by another person. It can only talk about impossible things (past actions performed by another person which we cannot change).

• The client was 10 minutes late for his appointment, so Paul left the office and went to lunch. I would have waited for at least 30 minutes. (Paul didn’t wait – but this would be my choice of action in the same situation)

• I wouldn’t have paid $500 dollars for that jacket. (You bought it, not me. It looks awful and I would only pay $50)

Can’t have + past participle

We use this form to explain that (in our opinion) something isn’t/wasn’t possible.

You can’t have seen Paolo in the office yesterday; he’s in Brazil on holiday (so it is not possible)

She can’t have forgotten about the meeting; I sent her an email about it yesterday

He’s only 20 so he can’t have finished university yet

Could / Couldn’t have + past participle

• ‘Could’ is the past participle of ‘can’ which is used to speak about ability. When we use ‘could have done’, we use it to speak about actions which a person had the ability to do, but did not do.

• I could have applied for a work visa when I was living in Japan but I decided to return home instead. (I had the ability / opportunity but did not do the action)

  He could have written the email before lunch, but he decided to do it in the afternoon.

Should (not) have + past participle

This form is used to talk about an action which somebody DID NOT do, but which we think was the correct action, or a good idea.

He shouldn’t have shouted. (He did, but the speaker thinks it was a bad idea)

He shouldn’t have resigned from his job before he found a new one.” (He resigned, but it was a mistake)

Paul shouldn’t have shouted at the manager. Now he’s going to get sacked.

Must have + past participle

This form expresses our certainty that something was true.

“I think Paolo must have killed his wife.” (I am certain this happened)

“We sent everybody an email, so Paul must have known that the meeting had been cancelled.”

Might (not) have + past participle

We use this form to talk about past possibilities.

Paolo might have stolen the money. (It’s possible)

Paul has visited the company several times, so he might have met the sales manager already.

Paolo wasn’t at the meeting, but he might not have received the email asking him to attend.

Needn’t have + past participle

This speaks about an action which a person DID do, but which was not necessary.


It didn’t rain today, so I needn’t have taken an umbrella to work. (I DID take an umbrella, but it wasn’t necessary)

You needn’t have bought me a birthday present. (Thank you, but it was not necessary)

Paul’s computer had a virus, but now it has been repaired, so he needn’t have bought a new one.

Multiple Choice

I didn't wake up early yesterday. I... (express regret)

• should have wake up early.

• should have wakes up early.

• should have woken up early.

Multiple Choice

Marta didn't do her homework. She...

• should have did it.

• should have done it.

• should have do it.

Multiple Choice

If Joanne had told the truth to her mother?

• I should not have lied

• I could not have lied

• She would not have been in restriction

Multiple Choice

My dad's car was making strange noises, but he didn't go to a mechanic. Now, it's broken. He...

• should've gone to a mechanic.

• should have went to a mechanic.

• should've go to a mechanic.

Multiple Choice

Tom didn't read the application, and now he regrets it. He...

• should read the application.

• should have red the application.

• should have read the application.

Multiple Choice

If Tanya had asked for permission

• shouldn't have come home late.

• She would have had permission to go out today

• She could have called them

Multiple Choice

You look really tired today. Last night you...

• should sleep more.

• should have sleep more.

• should have slept more.

Multiple Choice

If I had watched the movie,

• Should have know the story

• I would have known the story

• could have knew the story

Multiple Choice

I've got a terrible headache. I ..... my medicine.

• should've take

• should've took

• should've taken

Multiple Choice

If james had taken his medicine.

• He would have come to class

• He should have class

• He would class

The following sentences are about an escaped criminal. Rewrite them using a modal from the above table, as in the example. 

*It is almost certain that he left before breakfast.               

He must have left before breakfast.