Past Continuous Tense

1. Для выражения действия (состояния), которое продолжалось, когда совершалось другое действие: When he arrived home his sister was listening to the wireless. Whеге were you living when the war broke out? I saw Mr. Gray when I was walking to school. The boy was knocked down by a bus while he was crossing the street. Was it still raining when you came in? The sun was just setting as we reached home. I dropped my watch when I was winding it last night.
2. Когда нас интересует не столько момент или период совершения действия, сколько его протекание (сам процесс), причем, несущественно завершено оно или нет, а также подчеркивается ограниченная длительность процессов (в течение дня, вечера etc): What were you doing all morning? She was listening to the wireless all evening. They were making cakes this morning.
3. Когда необходимо показать одновременность нескольких действий: She was cleaning the window and he was polishing the forks and spoons.