Present simple – verb 'to be'
We can use the present simple of the verb to be to talk about situations and states in the present.
I am ten years old.
They are Egyptian.
My mum is a doctor.
How to use it
Use am for I. Use is for he, she and it. Use are for you, we and they. We can contract the verb, especially when we're speaking.
I am tall. = I'm tall.
You are my friend. = You're my friend.
My mum is a doctor. = My mum's a doctor.
We are doctors. = We're doctors.
They are Egyptian. = They're Egyptian.
For negatives, use not.
I am not nine years old! = I'm not nine years old!
She is not a teacher. = She's not a teacher. = She isn't a teacher.
They are not English. = They're not English. = They aren't English.
For questions, change the order of am, is or are and the person.
Are you Brazilian? Yes, I am.
Are they students? No, they're not.
Where is your brother?