You should... more responsible and hardworking, otherwise you'll lose your job.

• have been

• be

I don't understand how the accident has happened. The driver can't... the pedestrian crossing the street.

• have seen

• see

We planned to go abroad this summer but we didn't. We could..., but some unforeseen circumstances prevented us from doing this.

• have gone

• go

You needn't... him twice of anything. He was fully concentrated on his duties.

• have reminded

• remind

Mabel is well-educated and has good manners. She can't... like that.

• have behaved

• behave

The perfect Infinitive is a type of infinitive that is used to express an action that ...

• has happened in the past.

• that happens now.

Не может быть, чтобы он это купил.

• He can't have bought it.

• He might not have bought it

• He may not have bought it.

Clare was very upset you didn't go to her birthday party. You ... (to go).

If I had gone to the sales, I'm sure I ....(to buy) ... something.

Вам следовало бы выучить стихотворение лучше, однако вы этого не сделали.

• You should have learnt the poem better.

• You must have learnt the poem better

• You might have learnt the poem better.