Modals for speculating about the past

He __ committed the crime, as he had both the motive and the opportunity.

• should have

• could have

• must have

Lucy __ attended the concert, but we aren't sure.

• may have

• must have

• might have

I think they __ got lost - surely they'd be here by now!

• could have

• must have

• might have

Oh no! My phone isn't in my bag. I __ left it on the train.

• should have

• must have

• might have

She __ been a lawyer but she decided to study accountancy instead.

• could have

• may have

• might have

I'm sure she didn't visit us because she hadn't slept well. She ____ been really tired.

• could have

• must have

• should have

He's a gardener, he _____ been in the garden when I called.

• Must have

• Should have

• could have