1. They told me that I didn't have to do that if I didn't really want to.

Bởi vì câu này phải lùi thì từ HTĐ (don't) thành QKĐ (didn't) do nó ở dạng phủ định

2. He told me that he had seen Jim when he was walking home the day before.

Lùi thì từ  saw--->had seen 

3. Jane asked me whether I would forgive Jim if he apologized to me.

Lùi thì từ will---> would

4. I told Jane that Peter had been a friends of mine for 3 years.

Lùi thì has been---> had been

5. Jim wondered if he would be capable of winning that contest.

Lùi thì will---> would

6. John said that there had been  a serious car accident right there the week before.

Lùi thì  was---> had been

7. Jane told me he was frustrated that Jim forgot their date the day before.

Lùi thì am--->was

8. Peter said it was the first time he had been to NYC

Lùi thì  is--->was