Question

the books are excelente
i
n
my brother is five years old
i
n
he is chinese
i
n they are students
i
n

Answer 1

i- are the books excelent?
n- the books aren't "excelent" (good ficaria melhor)

i- is my brother five years old ?
n- my brother isn't five years old 

i- is he chinese ?
n- he's not chinese or he isn't chinese

i- are they students ?
n- they aren't ou they're not students !