UNIT 22 Modals 3: the modal perfect

MODAL + THE PERFECT INFINITIVE

modal + have + past participle

statement

negative

question

You should have told me you

You shouldn’t (should not)

Should I have invited

were going shopping.

have told Liz what Bill said.

Carol to the party?



WATCH OUT

Some verbs have irregular past participle forms. See page 182.

ABILITY

Use

Modal

Example

To say that someone had the

could

We could have gone to the party, but we

opportunity or ability to do

decided not to in the end.

something, but didn’t do it



WATCH OUT

We use this for things that someone didn’t actually do. For general ability in the past, we

use could + bare infinitive (see Unit 19).



I could play the guitar when I was seven. (= I knew how to play the guitar.)



I could have played the guitar. (= I had the opportunity to play the guitar, but I didn’t actually

play it.)

CRITISM

Use

Modal

Example

To say that someone’s past

ought to / should

You should have invited Carol to your

behaviour was bad or wrong

party

( = You didn’t invite Carol and that was wrong.)

EXPECTATION

Use

Modal

Example

To show you expected the past

ought to / should

Jim should have arrived half an to

be different from what actually

hour ago. I wonder where he is.

happened