Answer :

`1.` Are there forty classrooms in Thu's school?

`2.` Can you tell me about your neighborhood?

`3.` Nam's grandfather is the oldest person in his family.

`4.` You must do your homework before going to school.

`5.` Children should go to bed early.

`1.` Are there forty classrooms in Thu's school?

- Are there + số lượng + N + ....?

`2.` Can you tell me something about your neighborhood?

- Can + S + V-inf + ....?

`3.` Nam's grandfather is the oldest person in Nam's family.

- S + be + the + adj-est + N/pronoun

`4.` You must do your homework before going to school.

- S + must + V-inf + ....

`5.` Children should go to bed early,

- S + should + V-inf + ...