2, is buying (grandfather ⇒ chia số ít; buy ⇒buying)

3, is not studying (tên riêng ⇒ chia số ít; study ⇒ studying

4, Is she running (She ⇒ chia số ít; run ⇒ running)

5, is eating (dog ⇒ chia số ít; eat ⇒ eating)

6, are you waiting (you ⇒ chia số nhiều, wait ⇒ waiting)

7, are not trying (students ⇒ chia số nhiều, try ⇒ trying)

8, are having (All of + N ⇒ chia số nhiều, have ⇒ having)

9, are traveling (children ⇒ chia số nhiều, travel ⇒ traveling)

10, is drinking (little brother ⇒ chia số ít; drink ⇒ drinking)

11, is speaking (teacher ⇒ chia số ít; speak ⇒ speaking)

`2,` Is buying

`3,` Isn't studying

`4,` Is she running

`5,` Is eating

`6,` Are you waiting 

`7,` Aren't trying

`8,` Are having

`9,` Are travelling

`10,` Is speaking

`->` Cấu trúc thì hiện tại tiếp diễn:

$(+)$ S + is/ am/ are + V-ing + ...

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

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

* Trong đó:

`-` I + am

`-` She, he, it, N(số ít) + is

`-` We, you, they, N(số nhiều) + are