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Third conditional


We use the third conditional to describe unreal situations in the past and the imagined results. Both the situation and the result exist in the past; the situation did not happen so the result is impossible:

    If I had woken up earlier, I wouldn’t have missed the train.          The real situation and result: I didn’t wake up earlier so I missed the train.



We form the third conditional with a conditional clause and a main clause:
The order of the clauses does not matter: the meaning is the same.

If we put the conditional clause before the main clause, we use a comma:

Conditional clause Main clause
"If" + past perfect + comma "would have" + past participle
If I’d woken up earlier, I wouldn’t have missed the train.
If she hadn’t got the job, she would have been very disappointed.
If they had known about the problems with the trains, they would have driven instead.
If I hadn’t eaten the fish, would I have got sick?

We do not use a comma if we put the main clause before the conditional clause:

Main clause Conditional clause
"would have" + past participle "if" + past perfect
I wouldn’t have missed the train if I had woken up earlier.
She would have been very disappointed if she hadn’t got the job.
They would have driven if they had known about the problems with the trains.
Would I have got sick if I hadn’t eaten the fish?


  • They’d have passed their exams if they harder. (study)
  • If he had followed the directions, he on time. (arrive)
  • Would you have guessed the ending of the film if you the book. (not read)
  • Sarah would to Paris if she’d had enough time. (go)

Further practice

Complete the sentences to form the third conditional by choosing the correct answer from a, b, c or d:

Check my answers

Use of "could", "might"

We can use "could" or "might" instead of "would" in the main clause of the third conditional.