`@` Câu trần thuật ~ gián tiếp:

`-` S + said/told

`1`. He said that he didn't know what had happened.

`-` Lùi thì: HTĐ `->` QKĐ

                QKĐ `->` QKHT

`-` Đổi ngôi: I `->` he

`2`. She said that she had gone to the doctor the day before.

`-` Lùi thì: QKĐ `->` QKHT

`-` I `->` she

`-` Yesterday `->` the day before

`3`. He said that he had a toothache.

`-` Lùi thì: HTĐ `->` QKĐ

`-` I `->` he

`4`. She said that she would write him a prescription.

`-` Lùi thì: will `->` would

`-` I `->` she

`1.` He said that he didn't know what had happened

`2.` She said that she had gone to the doctor the day before

`3.` He said that he had a toothache

`4.` She said that she would write him a prescription

`***` Công thức câu trực tiếp - gián tiếp 

`@` Câu tường thuật 
`-` Trực tiếp : S1 + said (to O) "S2 + V2"

`-` Gián tiếp : S1 + said/told O (that) S(O) + V2(lùi thì)

`@` Các TH lùi thì trong bài :

HTĐ `->` QKĐ

QKĐ/HTHT `->` QKHT

Will `->` Would

`@` Các TH thay đổi adv thời gian trong bài :

Yesterday `->` the day before/the previous day

`@` Các TH thay đổi S trong bài :

I `->` he/she ( phụ thuộc vào đối tượng được nói tới )