To Be : AM - IS - ARE

Long form	Short form	Example	Negation
I am	I'm	I am late.	I am not late.
You are	You're	You are clever.	You are not (aren't) clever.
He is	He's	He is happy.	He is not (isn't) happy.
She is	She's	She is hungry.	She is not (isn't) hungry.
It is	It's	It is cold.	It is not (isn't) cold.
We are	We're	We are late.	We are not (aren't) late.
You are	You're	You are sleepy.	You are not (aren't) sleepy.
They are	They're	They are great.	They are not (aren't) great.