Verb to be (am, is, are)

The verb to be links the subject to a description, job, place, or state. In some languages you can drop the equivalent of “be”. In English, am / is / are is required.

Present Simple forms

I am → I'm
he / she / it is → he's, she's, it's
you / we / they are → you're, we're, they're

I am a student.
He is a doctor.
She is happy.
It is a book.
You are smart.
We are friends.
They are at home.

Negatives and questions

I am not tired. / I'm not tired.
She isn't at home. (is not)
They aren't ready.
Are you a student? — Yes, I am. / No, I'm not.
Is he Ukrainian?

Use: state, job, age, place, and as part of Present Continuous: I am reading now.