Perhaps he left the car unlocked. (PAST)
He might/could/may have left the car unlocked.
It is possible that you forgot your wallet at home. (PAST)
You might/could/may have forgotten your wallet at home.
I'm sure Jane is sleeping now. (PRESENT)
Jane must be sleeping now.
I'm sure she is at home today. (PRESENT)
She must be at home today.
Did you hear me come in last night? No, I ____ ____ ____ (BE) asleep.
must have been
I'm sure you didn't forget about your homework. (PAST)
You can't have forgotten about your homework.
I had an umbrella when I came out but I haven't got it now. I _____ ____ ____ (LEAVE) it on the bus, but I'm not sure.
might/could/may have left
Kate is shivering. She ____ be cold. (PRESENT)
must
It is impossible that he is 65 years old. (PRESENT)
He can't be 65 years old.
John will probably come to the party. (PRESENT)
He may/might/could come to the party.
Emily is crying because her doll has broken. She ____ be sad. (PRESENT)
must
I'm sure they aren't at work today. (PRESENT)
They can't be at work today.
