改成否定和肯定Are you an English boy?Is the girl your friend?Is her

Are you an English boy? 肯定：You are an English boy. 否定:You are not an English boy. Is the girl your friend?肯定that girl is your friend. 否定that girl is not your friend. Is her brother David?肯定her brother is david. 否定her brother is not David. Is your pencil case red?肯定 your pencil case is red. 否定your pencil case is not red. 应该正确吧,因为我在加拿大上学.

you are(not) an English boy
the girl is(not0 your friend
her brother is(not) David
your pencil case is(not) red？