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

`1`.

`(-)` Tom didn't go to the hospital to provide food to weeks ago 

`(?)` Did Tom go to the hospital to provide food to weeks ago ?

`2`.

`(-)` The sidewalks were not wet after the rain 

`(?)` Were the sidewalks wet after the rain ?

`3`.

`(-)` I didn't start to work as a volunteer three years ago

`(?)` Did you start to work as a volunteer three years ago?

`4`. 

`(-)` They were not in the library an hour ago

`(?)` Were they in the library an hour ago?

`5`.

`(-)` Tom and his friend did not go to orphanages to learn english yesterday 

`(?)` Did Tom and his friend go to orphanages to learn english yesterday?

`---------`

`@` 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?

`1.` 

`(-)` Tom didn't go to the hospital to provide food two weeks ago

`(?)` Did Tom go to the hospital to provide food two weeks ago?

`2.`

`(-)` The sidewalks were not wet after the rain

`(?)` Were the sidewalks met after the rain?

`3.`

`(-)` They were not in the library an hour ago

`(?)` Were They in the library an hour ago?

`4.`

`(-)` Tom and his friends didn't go to orphanages to learn English yesterday

`(?)` Did Tom and his friends go to orphanages to learn English yesterday?

`____________________`

`***` QKĐ:

`+` Tobe:
`(+)` S + was/were + N/adj

`(-)` S + was/were + not + N/adj

`(?)` Was/were + S + N/adj?

`*` I/ he / she / it / DTSI + was

`*` you / we / they / DTSN + were

`+` Verb:
`(+)` S + V2/ed + O
`(-)` S  + didn't +  V_inf + O

`(?)` Did + S +  V_inf + O?
`-` DHNB: last + week/month/... , yesterday, ago , ...