$\longrightarrow$  S + Vs / es

$\longrightarrow$  S + Ved / V2

$\longrightarrow$ S + used to + V-inf

5. When does he do his homework ?

6. He didn't do anything yesterday

7. Nga's grandmother used to tell her old folktales when she was a little girl

`1.` When does he do his homework?

`-` Nghi vấn hiện tại : Wh-ques + do/does + S + V-inf + O ?

`2.` He didn't do anything yesterday.

`-` yesterday là dấu hiệu chia thì QKĐ ( Phủ định : S + didn't + V-inf.... )

`3.` Nga's grandmother used to tell her old folktales by when she was a little girl.

`-` used + to V-inf : đã từng làm gì trong quá khứ