B2 · grammar

Third Conditional Exercises (B2) — Free

Third conditional: imagining a different past and its result

The third conditional imagines a past that didn't happen and its imaginary result: If + past perfect, would have + past participle (If I had known, I would have helped). Because the past can't change, it's often used for regrets and criticism: If we had left earlier, we wouldn't have missed the train (but we didn't leave earlier, and we missed it). The two clauses can go in either order; use a comma only when the if-clause comes first. In speech, both had and would contract to 'd: If you'd told me, I'd have helped you. The 'd in the if-clause is always had; the 'd before have is always would. A common mistake is putting would in the if-clause: say 'If I had known', not 'If I would have known'. Could have or might have can replace would have for a result that is possible rather than certain (If she had studied harder, she might have passed).