The verb "to be"

The verb to be in the Present Simple Tense

POSITIVE FORM

I am (I'm)
You are (you're)
He is (he's)
She is (she's)
It is (it's)
We are (we're)
You are (you're)
They are (they're)

NEGATIVE FORM

I am not (I'm not)
You are not (you're not or you aren't)
He is not (he's not or he isn't)
She is not (she's not or she isn't)
It is not (it's not or it isn't)
We are not (we're not or we aren't)
You are not (you're not or you aren't)
They are not (they're not or they aren't)

Am I?
Are you?
Is he?
Is she?
Is it?
Are we?
Are you?
Are they?

For example:

Today is Monday. - Сегодня понедельник.
Peter is a teacher. - Петр - учитель.
The lamp is on the table. - Лампа на столе.
The railway station is in the centre of the city. - Вокзал находится в центре города.

1. Short answers

1.1. Nouns - pronouns.

Are your parents at work?
Yes, they are.

1.2. Positive short answers do not use cotractions:

Are you a student?
Yes, I am.
Are they in Moscow?
Yes, they are.

1.3. Cotractions are used in negative short answers:

Is she a teacher?
No, she isn't.

2. Questions with WHAT, WHO, WHERE, WHY, HOW

Who is that girl?
What is on the table?
Where are the children?
How old are you?