Could have should have would have

I (a)   (buy) bread but I didn't know we needed it. (past possibility)

We (a)   (invite) so many people to our party! I'm worried that we won't have enough room for everyone. (past negative advice / regret)

I (a)   (start) saving money years ago! (past advice / regret)

We (a)   (join) you at the restaurant, but we couldn't get a babysitter. (past willingness)

The weather (be) (a)   any worse! (past negative possibility)

I (a)   (arrive) on time, even if I'd left earlier. There were dreadful traffic jams all the way. (past negative possibility)

They (a)   (win) the football match, but John hurt his ankle. (past possibility)

Amanda (a)   (finish) the work, but she felt ill and had to go home. (past willingness)

We (a)   (finish) the game, even if we'd wanted to. It was raining very hard and we had to stop. (past negative possibility)

I (a)   (eat) so much chocolate! I feel sick! (past negative advice / regret)