Modal Verbs of Possibility for Past Situations

The twins have guilty expressions on their faces. They _____

• might have done something naughty.

• must have done something naughty.

• might do something naughty.

• must do something naughty.

Our son promised to clean his room, but it is still messy. He _____

• couldn't have cleaned it.

• cannot clean it.

• couldn't to have cleaned it.

• can't clean it.

My plants are dead. I _____

• couldn't give them enough water.

• must give them more water.

• can't have given them enough water.

• can't not have given them enough water.

The hockey player's injury kept him out of the Stanley Cup Playoffs. He _____

• must have been disappointing.

• might have been disappointed.

• must have been disappointed.

• must have been disappointment.

Betty said she was hungry, but she didn't eat very much after all. She _____

• couldn't have been hungry.

• can't like the food.

• couldn't have liked the food.

• couldn't like the food.

My friend promised to pick me up at 7:00. It's now 7:25 and I don't see him. He _____

• might forget.

• must have forgotten.

• might have forgotten.

• might be forgetting.

I don't know why he hasn't called me back. He _____

• might forget my number.

• might be forgetting my number.

• must have forgotten my number.

• might have forgotten my number.

Look! Our car isn't in the driveway! Somebody _____

• might have stolen it.

• could have stolen it.

• must be stealing it.

• must have stolen it.

Paul's class starts at 8:30. It's 8:45 and he's not here yet. He _____

• must be sick.

• might have missed the bus.

• must have been sick.

• must have missed the bus.

My white shirt now has green streaks in it. I _____

• can't have washed it properly.

• must to wash it properly.

• must not have not washed it properly.

• can't wash it properly.