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

`1`.

`(-)` I am not doing my homework now

`(?)` Are you doing your homework now?

`2`.

`(-)` They are not playing soccer at the moment

`(?)` Are they playing soccer at the moment?

`3`.

`(-)` Hoa is not writing a letter now

`(?)` Is Hoa writing a letter now?

`4`.

`(-)` My children are not eating breakfast now

`(?)` Are the children eating breakfast now?

`5`. 

`(-)` His brother is not walking to school at the moment?

`(?)` Is his brother walking to school at the moment?

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

`@` HTTD

`(+)` S + am/is/are + V-ing + O

`(-)` S + am/is/are + not + V-ing + O

`(?)` Am/is/are + S + V-ing + O?

`@` DHNB : now, right now, at the moment, at present,...

`1.`

(-) I'm not doing my homework now.

(?) Are you doing your homework now?

`2.`

(-) They aren't playing soccer at the moment.

(?) Are they playing soccer at the moment?

`3.`

(-) Hoa isn't writing a letter now.

(?) Is Hoa writing a letter now?

`4.`

(-) My children aren't eating breakfast now.

(?) Are your children eating breakfast now?

`5.` 

(-) His brother isn't walking to school at the moment.

(?) Is his brother walking to school at the moment?

-------------------

`-` HTTD (DHNB: now, at the moment):

(+) S+ is/am/are+V-ing+O

(-) S+ is/am/are+ not+V-ing+O

(?) Is/am/are + S+ V-ing+O?