1 He wanted to know why I was standing there.

câu tường thuật nên lùi thì,here→there

2 She hasn't written to her sister since September.

have/has +V3/ed ( hiện tại hoàn thành)

3 Jane used to get good marks when she was a student/

used to+ V0 ( miêu tả hành động, sự việc hay diễn ra ở quá khứ nhưng không còn ở hiện tại)

4 If I had enough money, I could buy a new house.

câu điều kiện loại 2: diễn đạt tình huống không có thật ở hiện tại hay tương lai

5 She said she had studied English for several years.

câu tường thuật nên lùi thì: present perfect→past perfect 

1.He wanted to know why she was standing there

2.She hasn't written to her sister since last September

3,Jane used to get good marks when she was a student

4.If I had enough money , I could buy a new house

5.She said that she had studied English for several years