Mỗi câu sau chứa một lỗi sai

Mỗi câu sau chứa một lỗi sai. Tìm và
sửa chúng.
1. Before they came to visit my
grandparents, I have already cleaned
the house.
2. After Jimmy had gone home, I was
doing the shopping.
3. She had come to the cinema before
I do.
4. When they arrived, John goes
away.
5. I had prepared for the exam and am
ready to do well.
6.No sooner had Mimi started her
walk when it started to rain.
7.No sooner have I left the school than
it started raining.
8.Tom had hardly arrived at the
station while the train came.
9.Hardly i had just put the phone
down when the boss rang back.
10. We had no sooner started cook
than there was a power cut and we
had no electricity.
11.They no sooner arrived than they
were arguing.
12. he had hardly left the office when
the telephone rings.