You (be) rude to him. He's going to be really angry now. (past negative advice / regret)
shouldn't have been
You (take) this job. I can see you're not enjoying it. (past negative advice / regret)
shouldn't have taken
They (be) kinder to me. They were absolutely lovely. (past negative possibility)
couldn't have been
We (join) you at the restaurant, but we couldn't get a babysitter. (past willingness)
would have joined
Why were there no buses yesterday? Maybe it was the snow or they must have/ might have / couldn't have been on strike.
might have
Luke (pass) the exam if he'd studied a bit more. (past possibility)
could have passed
Lucy (leave) earlier. She missed her flight. (past advice / regret)
should have left
I (eat) so much chocolate! I feel sick! (past negative advice / regret)
shouldn't have eaten
Andrew (go) to Cambridge University, but he decided to travel instead. (past possibility)
could have gone
You must have / might have / can't have /seen her, surely! She was standing right in front of you.
must have
Our neighbours (cut) down the tree in their garden. It was a really beautiful tree. (past negative advice / regret)
shouldn't have cut
I'm really cold! I (bring) my coat. (past advice / regret)
should have brought
We (invite) so many people to our party! I'm worried that we won't have enough room for everyone. (past negative advice / regret)
shouldn't have invited