17. She asked if I could help her.
Ta có cấu trúc của câu là:S + asked + (O) + if + S + V
18.They said (that) I had to wash my hands.
Ta có cấu trúc của câu là:S + said + (that) + S + V 
19.. They said (that) it wouldn't rain the next day.
20. He said (that) he should learn Spanish.
21.He said (that) he couldn't drive a lorry
22. He asked if I would have dinner with him.
23.He asked if he should carry my suitcase.
Nếu bạn thấy hay thì vote 5 sao+Ctlhn ạ
Chúc bạn học tốt ^^
#Phuc

REPORTED SPEECH : 

Present Simple -> Past Simple

Present Continuous -> Past Continuous 

Past Simple -> Past Perfect

Present Perfect -> Past Perfect 

Future Simple (will) -> Future Simple (would)

Yesterday -> The day before 

Today -> That day

Tomorrow -> The following day/The day after 

Here -> There

This -> That

These -> Those

Tonight -> That night 

Can/Can't -> Could/ Couldn't

Must/Have to -> Had to

Will/Won't/Shall -> Would/Wouldn't 

May -> Might

17. She asked me if I could help her.

( Trong câu tường thuật thì câu hỏi phải ở thế Xác Định)

18. They said that I had to wash my hands.

19. They said it wouldn't rain tomorrow.

20. He said he should learn Spanish.

21. He said he couldn't drive a lorry.

22. He asked if I would have dinner with him.

23. He asked if he would carry my suitcase.