`1.` What did they do at school?
`2.` Who was a worker?

`3.` How were you when you were young?
`4.` Did she like music?

`5.` Where did you study Maths?

`_________________`

`-` what : cái gì 

`-` who : ai `-` thay thế cho người

`-` how : như thế nào

`-` where : ở đâu `-` hỏi nơi chốn, địa điểm

`-` QKĐ:
`+` Tobe: `(?)` Was/were + S + N/adj?

`+` Verb: `(?)` Did + S + V_inf + O?

$\begin{array}{c} \color{#db1616}{\texttt{#NUyen}} \end{array}$

`1`. What did they do at school?

`-` What : cái gì 

`2`. Who was a woker?

`-` Who : ai `->` hỏi người

`3`. How were you when you were young?

`-` How : như thế nào, bằng cách nào

`4`. Did she like music?

`5`. Where did you study Maths?

`-` Where : ở đâu `->` hỏi địa điểm

`----------`

`@` QKĐ

`***` Công thức V tobe

`(+)` S + was/were + ...

`(-)` S + was/were + not + ...

`(?)` Was/were + S + ... ?

`***` Công thức V thường

`(+)` S + V(ed/qk)

`(-)` S + didn't + V(bare) + O

`(?)` Did + S + V(bare) + O?