47. She told John that she would show him round her city when he was there.

S + told + O + that+ S+ V (lùi thì)

will ⇒ would 

HTĐ ⇒ QKĐ

here ⇒ there

48. You don't have to finish the report until tomorrow afternoon. (sửa đề: you have--> you don't have)

(not) have to + V1: (không) phải làm gì 

49. I wish I could speak Chinese.

S + wish(es) +S+ could  +V1: ước ở hiện tại 

50. If we didn't live in a big city, we couldn't get access to the Internet easily.

if 2: If + QKD, S + would / could + V1 

`color{orange}{~MiaMB~}`