If + past perfect, subject + « would have » + past participle ….
3rd conditional = « if + past perfect », … « would have » + past participle
3rd Conditional about impossible conditions because they are in the past:
Past situation => we can’t change it => impossible situation.
We describe a situation that didn’t happen, and we imagine the result of it.
if you HAD KNOWN, you WOULD + HAVE + DONE
If you + HAD + PAST PARTICIPLE, you + WOULD HAVE + PAST PARTICIPLE …
If I had worked harder my lesson, I would have got a better mark.
If I had studied, I would have passed the exam (I didn’t studied => I did’nt pass the exam).
If you had gone to bed earlier yesterday, you wouldn’t have been tired today.
If you had bought this house, you would have had to repaint the room.
If he had taken a taxi, he wouldn’t have missed the plane.
If she hadn’t eaten too much, she wouldn’t have done a diet.
If we had known this, we would have visited the museum.
If we had caught the earlier plane, we would have got here on time.
If you had studied harder, we would have finished the program.
If you had gone to university, you would have become a doctor.
If they had known it, they would have made it differently.
They would have been on time if they had left the house earlier.
Main clause with « would », « could » or « might »:
If I had known this … :
-> I would have made it. (I didn’t know it, so I didn’t make it).
-> I could have made it. (I didn’t know it, so I couldn’t make it).
-> I might have made it. (I might have made it maybe, but it’s not sure!).
3rd conditional without the « if clause »:
You would have been on time with the earlier plane. (if you had caught it).
I could have got a better mark. (if I had worked harder my lessons).
I might have changed my mind. (if I had known this problem).
=> Here, in these sentences, the « if clause » is not spoken.