Past Perfect Tense. Use #3: Unreal or Imaginary Things in the Past
In the same way that we use the past simple to talk about unreal
or imaginary things in the present, we use the past perfect (one step back in
time) to talk about unreal or imaginary things in the past. This is common in the third
conditional, and after “wish”.
Example: If I had
known you were ill, I would have sent you some flowers.- Если бы я знал, что ты болен, я бы отправил тебе
цветы.