1) Is she a teacher?
Are him and you best friends?
Is she an english teacher?
Are they sisters?

2) Afirmativas: She is a teacher 
                      Him are and you best friends
                      She is an english teacher
                     They are sisters
Negativas: She isn't a teacher
                Him aren't and you best friends
                She isn't a english teacher
                They aren't sisters
Espero ter ajudado (: