← C1

Degrees of certainty about past events

Objective: Express strong conclusions, impossibility and uncertainty about events in the past.

Explanation

Use must have for a strong logical conclusion, cannot or could not have for an impossible conclusion, and may, might or could have for an uncertain possibility.

Examples

Practice

Choose the correct answer.

The lights are off and the car is gone. They ___ already.

Practice

Choose the correct answer.

He knew nothing about the change, so he ___ the email.

Practice

Choose the correct answer.

The taxi arrived late because it ___ in traffic.