Had you been waiting there for more than two hours when she finally arrived? (общий) How long had you been studying Turkish before you moved to Ankara? (специальный) Who had been waiting for three hours to get on the bus? (к подлежащему) She had been working at that company for three years when it went out of business, hadn't she? (разделительный) Had James been teaching at the university or at school for more than a year before he left for Asia? (альтернативный)
How long had you been studying Turkish before you moved to Ankara? (специальный)
Who had been waiting for three hours to get on the bus? (к подлежащему)
She had been working at that company for three years when it went out of business, hadn't she? (разделительный)
Had James been teaching at the university or at school for more than a year before he left for Asia? (альтернативный)