Example: “If you had called me, I would have come.”
Notice that in this sentence a past perfect tense is used in the if-clause; a past conditional (‘would have’ + past participle of the verb) is used in the main clause.
We use this conditional to talk about things in the past happening differently from the way they really happened. This sometimes means :
1. criticizing people, 2. pointing out their mistakes or 3. expressing regret about the past.
Try the 3rd Conditional Exercise below!