Объясните мне пожалуйста в английском языке время Past Perfect Continuous! Заранее спасибо!!!

Спасибо большое!!!

Время Past Perfect Continuous указывает на действие, которое началось в прошлом, продолжалось в течение некоторого времени и либо закончилось непосредственно перед неким моментом в прошлом или все еще не закончилось к некоему моменту в прошлом.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.Образование Past Perfect ContinuousУтвердительные предложения:I had been playing We had been playingYou had been playing You had been playingHe / she / it had been playing They had been playingВопросительные предложения:Had I been playing? Had we been playing?Had you been playing? Had you been playing?Had he / she / been playing? Had they been playing?Отрицательные предложения:I had not been playing We had not been playingYou had not been playing You had not been playingHe / she / it had not been playing They had not been playingДля того, чтобы поставить глагол в форму времени Past Perfect Continuous, требуется вспомогательный глагол to be во времени Past Perfect и причастие настоящего времени (форма V-ing) смыслового глагола.