I should have studied medicine.
She shouldn’t have divorced Ali.

The heating was working so they will have been cold.
There’s no food in the fridge – she must have eaten it all.

Someone phoned you earlier, it might have been Jim but I’m not sure.
She’s very late. She may have broken down.
I don’t know where he is, he could have gone for lunch.

Mark can’t have gone to Benenden- It’s a girls’ school.
It’s only 5 o’clock. They won’t have arrived home yet.