Present
She's yawning a lot. She ______ (be) very sleepy.
must be
Listen! Someone ____________ the piano upstairs. It's very clear.
must be playing
He was soaking wet. He __________ (walk) in the rain.
might have walked
I'm sure she didn't know about the test.
She couldn't have known about the test.
They ______ (be) on holiday. Their house is dark.
might be
The lights are on. But no one is answering the door. They __________.
might be sleeping
He ____________ (not see) me - I was right in front of him.
couldn't have seen/can't have seen
It's possible she's studying right now.
She might be studying right now.
This restaurant is empty. It _______ (be) very good.
might not be / couldn't be
must be studying
He ___________ (take) the wrong train. He was in the wrong city.
might have taken
It's impossible that she's working today - It's her day off.
She can't be working today - It's her day off.
He ________ (know) the answer. He's smiling confidently.
must know
Look at his hands - they're covered in paint. He _______ (paint) something right now.
must be painting.
We ___________ (miss) the announcement. Nobody told us anything.
must have missed
She definitely didn't send the email - I checked her mailbox.
She couldn't have sent the email - I checked her mailbox.
That guy looks familiar. But I'm sure he lives abroad. It ________ (be) him.
can't be
They have been whispering all morning. They __________ (plan) something.
could be planning
couldn't have been
Maybe they didn't hear the doorbell.
They couldn't have heard the doorbell.