1.
a) I am not a teacher.
b) It isn't my cat.
c) You are not a student.
d) He is not a singer.
e) She isn't tall.
f) It is not a pen.
g) You aren't happy.
h) We are not Brazilian.
2.
a) Am I a teacher?
b) Is It my cat?
c) Are you a student?
d) Is he a singer?
e) Is she tall?
f) Is it a pen?
g) Are you happy?
h) Are we Brazilian?
(*) Lembrando que Isn't é a forma contraída de Is not, e Aren't é a forma contraída de Are not, então tanto faz, você usa qual quiser.
Espero ter ajudado! ^-^
