`1` 

`(+)` Lan studies the lesson everyday.

`(-)` Lan doesn't study the lesson everyday.

`(?)` Does Lan study the lesson everyday.

`=>` Câu hiện tại đơn

`(+)` S + V-inf / s;es + .....

`(-)` S + don't / doesn't + V_inf + ....

`(?)` Do / does + S + V-inf + ...... ?

`-` Lan là số ít nên chia với v-s;es / does và doesn't

`DHNB`: everyday

`2` 

`(+)` The students are having breakfast at school now.

`(-)` The students aren't having breakfast at school now.

`(?)` Are the students having breakfast at school now?

`=>` Công thức hiện tại tiếp diễn

`(+)` S +  to be ( am / is / are ) + v-ing + ....

`(-)` S + to be + not + v-ing + ....

`(?)` To be + S + v-ing + .......?

`-` The students là số nhiều nên chia với are

`DHNB`: now

`3`

`(+)` I am riding a bike at present.

`(-)` I am not riding a bike at present

`(?)` Am i riding a bike at present?

`=>` Công thức hiện tại tiếp diễn

`(+)` S +  to be ( am / is / are ) + v-ing + ....

`(-)` S + to be + not + v-ing + ....

`(?)` To be + S + v-ing + .......?

`-` I được chia với am

`DHNB`: at present 

$\text{1.}$ Lan studies the lesson everyday.

→ Lan doesn't study the lesson everyday.

→ Does Lan study the lesson everyday ? 

$\text{2.}$ The students are having breakfast at school now.

→ The students aren't having breakfast at school now. 

→ Are the students having breakfast at school now ?

$\text{3.}$ I am riding a bike at present. 

→ I am not riding a bike at present . 

→ Am I riding a bike at present ?

$\Rightarrow$ I/we/you/they + V-inf , He/she/it + V(s/es) 

$\Rightarrow$ S + don't/doesn't + V-inf 

$\Rightarrow$ Do/does + S + V-inf ? 

$\Rightarrow$ S + is/am/are + (not) + V-ing

$\Rightarrow$ Is/am/are + S + V-ing ? 

$\textit{#Yang Heun}$