1.You're in my class.
Are you in my class?
You aren't in my class.
2.It is a nice day.
Is it a nice day?
It isn't a nice day.
3.I'm 14 years old.
Am I 14 years old?
I am not 14 years old.
4.Your cousins are in Russia.
Are your cousins in Russia?
Your cousins aren't in Russia.
5.We are parents.
Are we parents?
We aren't parents.