1."Can I borrow your ruler,Linh?"Hoa said

->Hoa asked Linh  if she could borrow her ruler

2.Will you go to Brazil next month?"he said

-> He asked me if I would go to Brazil the following month

3.My friend said"ARe you going to leave tomorrow?"

-> My friend asked me if I was going to leave the following day

4."Have you done your homework?"said my mother

-> My mother asked me if I had done my homework

5.:Must you go now?"said Mr.brown

-> Mr. Brown asked me if I had to go then 

6.Mary asked me:"Can you tell me why you are so sad?"

-> Mary asked me if I could tell her why I was so sad

7.I asked the policeman,"Do you know how far it is to the movie theater?"

-> I asked the policeman if he knew how far it was to the movie theater

@linhhuong

1: Hoa asked Linh if she could borrow her ruler
2: He asked me if I would go to Brazil the following month
3: My friend asked me if I were going to leave the following day
4: My mother asked me if I had done my homework
5: Mr. Brown asked me if I had to go then
6: Mary asked me if I could tell her why I was so sad
7: I asked the policeman if he knew how far it was to the movie theater