Third conditional
B1 IntermediateThe third conditional describes hypothetical situations in the past and their imagined results. It is used to express regrets or to discuss how things could have been different.
Overview
The third conditional refers to impossible conditions because they happened in the past and cannot be changed. It connects a past action that did not happen to a past result that also did not happen.
- It is often used to express regret.
- It can be used to criticize someone's past behavior.
- The order of the clauses can be reversed without changing the meaning.
Form
If + past perfect, ... would have + past participle
The 'if' clause uses the past perfect, and the main clause uses 'would have' followed by a past participle.
Examples
Common mistakes
If I would have known, I would have told you.
If I had known, I would have told you.
Do not use 'would' in the 'if' clause. Use the past perfect instead.
If he had stayed, he would has seen her.
If he had stayed, he would have seen her.
Always use 'have' after 'would', even for third-person subjects like he, she, or it.
Second vs. Third Conditional
While the second conditional imagines a different present, the third conditional imagines a different past.
| Conditional | Time Reference | Reality |
|---|---|---|
| Second | Present/Future | Unlikely or imaginary |
| Third | Past | Impossible (already happened) |
Practice
Complete the sentence: If she ___ (see) the sign, she wouldn't have parked there.
Show answer
had seen
Answer:had seen
Why:The 'if' clause of the third conditional requires the past perfect (had + past participle).
Complete the sentence: We ___ (buy) that house if it had been cheaper.
Show answer
would have bought
Answer:would have bought
Why:The result clause of the third conditional uses 'would have' plus the past participle.
Rewrite the reality into a third conditional: I didn't call him because I lost his number.
Show answer
If I hadn't lost his number, I would have called him.
Answer:If I hadn't lost his number, I would have called him.
Why:To imagine the opposite of a past reality, use the negative past perfect in the 'if' clause and 'would have' in the result clause.