Used to express conditions in the past that did not happen. Often used to express criticism or regret with would have, could have or should have.
Uses the past perfect tense:-
|If I had worked harder,||I would have passed my exam.|
|If I had worked harder,||I could have passed my exam.|
|If I had worked harder,||I should have passed my exam.|
|I would have passed my exam||if I had worked harder.|
|I could have passed my exam||if I had worked harder.|
|I should have passed my exam||if I had worked harder.|
Note! We never use would have, or wouldn't have etc in the if clause.
- If I hadn't helped you, you would have failed. = You would have failed, if I hadn't helped you. (I helped you so you didn't fail).
- If it had been sunny, we could have gone out. = We could have gone out, if it had been. (We didn't go out because it wasn't sunny).