если бы я знал, что

if I had known that

→ если

phrase Rare #46,033

if I had known that Introduces a hypothetical past condition. The particle бы marks the counterfactual meaning; the following clause usually describes what would have happened as a result.

RU: Если бы я знал, что ты приедешь, я бы приготовил ужин.

EN: If I had known that you were coming, I would have prepared dinner.

Если бы я знал, что Том в больнице, я бы его навестил.

If I had known that Tom was in the hospital, I would have visited him.

Если бы я знал, что Том в Бостоне, то постарался б его навестить.

If I had known Tom was in Boston, I would have tried to visit him.

Если бы я знал, что ты там, я бы сразу пришел.

If I had known you were there, I would have come straight away.