If clause                       + main clause

If+ past perfect            + would / could /  might + present perfect


If I had understood the lesson, I would have approved the test.

If he had found the key, he would have opened the door.


  •  Underline the correct form of the verbs.
  1. If he hadn’t committed a crime, he wouldn’t be / wouldn’t have been arrested.
  2. If the hotel hadn’t been so expensive, we would have stayed / stayed / will stay there.
  3. We arrived / will arrive / would´ve arrived on time if we hadn’t got lost.
  4. I would have visited / would visit / will visit him if I had known that he was in hospital.
  5. If you didn’t leave / hadn’t left the door open, the dog wouldn’t have eaten our lunch.
  6. The holiday would’ve been / was / would be great if the weather had been better.
  •  Write the correct form of the verbs in brackets.
  1. If they _______________ (close) the gate, the dog wouldn’t have got out.
  2. They would’ve let us in if you  _______________ ( not lose) the tickets.
  3. He  _______________( not see) us if you hadn’t made a noise.
  4. I _______________(buy) a present if I had known it was your birthday.
  5. If the pilot  _______________(not be so experienced, the plane would have crashed.
  1. You  _______________(pass) your driving test, if you hadn’t been so nervous.
  •  Rewrite the sentences using the third conditional.
  1. He drank a lot so he had an accident.

If he _______________________________________________________

  1. I fell down the stairs because it was very dark.

If it ________________________________________________________

  1. Carol felt sick because she forgot to take her medicine.

She ________________________________________________________

  1. His parents were cruel to him so he ran away.

He _________________________________________________________

  1. I got up late because my alarm clock didn’t ring.

If ___________________________________________________________

  • Answer key


  1. wouldn’t have been
  2. would have stayed
  3. would’ve arrived
  4. would have visited
  5. hadn’t left
  6. would’ve been


  1. had closed
  2. hadn’t lost
  3. wouldn’t have seen
  4. would’ve bought
  5. hadn’t been
  6. would’ve passed


  1. hadn’t drunk so much, he wouldn’t have had an accident.
  2. hadn’t been so dark, I wouldn’t have fallen down  the stairs.
  3. wouldn’t have felt sick if she hadn’t forgotten to take her medicine.
  4. wouldn’t have run away if his parents hadn’t been cruel to him.
  5. my alarm clock had rung, I wouldn´t have got up late