Use the present continuous to talk about things that are happening now. The present continuous is formed with be + the verb + -ing. You can also use contractions.
I am working. = I'm working.
You are working. = You're working.
We are working. = We're working.
They are working. = They're working.
She is working. = She's working.
For negative sentences, add not. You can also use negative contractions.
I am not working. = I'm not working.
You are not working = You're not working. OR You aren't working.
We are not working = We're not working. OR We aren't working.
They are not working = They're not working. OR They aren't working.
She is not working. = She's not working. OR She isn't working.
For yes/no questions, start with the form of be.
A: Are you coming?
B: Yes I am. / No I'm not.
A: Is Chris leaving?
B: Yes he is. / No he's not.
For information questions, start with the question word + the form of be.
A: What are they doing?
B: They're studying.
A: Where are we going?
B: We're going to the mall.