`1.` Lan's father often drives to work.

`→` Lan's father often goes to work by car.

`-` HTD : S + V(s/es)...

`2.` Let's go out for a walk.

`→` Why don't we go out for a walk`?`

`-` HTD : S + do/does + not + V-inf

`3.` Does Nga's school have sixteen classrooms`?`

`→` Are there sixteen classrooms in Nga's school`?`

`-` There are/Are there + N đếm được số nhiều

`4.` What is the length of this river`?`

`→` How long is this river`?`

`-` How ....is ....?

`-` What's the ... of ...?

$\color{#88DCFF}{\text{#Byen.}}$

`1` Lan's father often goes to work by car

`->` S + V(s/es)

`->` go + to V/V-ing

`2` Why don't we go out for a walk

`->` Let's + V-inf

`=` Why don't we + V-inf?

`3` Are there sixteen classrooms in Nga’s school?

`->` There are + N ( số nhiều )

`4` How long is this river? 

`->` What + tobe + N?

`->` How + adj + tobe + N?