Read about using third conditionals below. Then, when you are ready, try these third conditional practice exercises.
Using the third conditional
Third conditionals are used to talk about imagined past situations and their imagined past results.
For example, Karen was sick because she ate some bad seafood. To imagine the alternative, I say ...
If Karen hadn't eaten those prawns, she wouldn't have been sick.
We often use this form to describe regrets or give blame:
If I'd studied harder, I'd have got an 'A'. (a regret)
If you'd been on time, we wouldn't have missed the film. (I blame you!)
How to make the third conditional
If + had(n't) + past participle (for the imagined past situation), would(n't) have + past participle (for the imagined past result)
If he had told the truth, I wouldn't have believed him.
It doesn't matter if you say the situation or the result first.
If he had driven more slowly, he wouldn't have crashed.
= He wouldn't have crashed if he had driven more slowly.
Third Conditional: Advanced Points
As well as would have, you can use might have or could have + past participle to talk about the result.
If I'd been less hungry, ...
... I wouldn't have eaten all your biscuits.
... I might have eaten less.
... I could have waited until dinner time.
Now, try these third conditional practice exercises.