PAST PERFECT CONTINUOUS : I had been typing this text for 2 hours and then found it on the Internet.
Я набирал этот текст два часа, а потом нашел его в Интернете.
I had been waiting for his airplane for 2 hours when it was announced about delay.
Я ждал его самолет уже два часа, когда объявили об его задержке.
I saw many puddles. Had it been raining?
Я видел много луж. Шел дождь?