=>
5. Mai said to Nam that she couldn't go to the movies with him.
Cannot -> Could not/couldn't
6. Tom said that he had already had breakfast, so he wasn't angry.
Lùi thì HTHT -> QKHT/ HTĐ -> QKĐ
7. I said to Nick that he didn't have to do it then, he could do it the following day.
Right now -> then/ tomorrow -> the following day
8. He said to them that my supervisor would be there in five minutes.
Will -> would/ here -> there
9. She said to me that she wanted to lend me her bike, but her brother had broken it the day before.
Yesterday -> the day before
10. The mother said to me that the sun rises in the East.
Một sự thật hiển nhiên -> không lùi thì