过去进行时：过去正在发生的事情
我昨天晚上11.00正在睡觉
1>
I was sleeping at 11.00 last night
he was sleeping at 11.00 last night
you were sleeping at 11.00 last night
2>迁移
I was going to being at the weekend
he was bying a car back home at 9.00 last night
you were learning English
3>迁移
was he bying a car back home ?
were you learning English?
4>自发迁移
