Am/Is/Are — As you will see in the next section, these are the three present tense forms of to be. Am is for the first person singular (I am), is is for the third person singular (he is, she is, it is) and are is for the first person plural (we are), the second person singular and plural (you are) and the third person plural (they are).
Was/Were — These two verb forms are used for the past tense. Was is used for the first and the third person singular (I was, he was, she was, it was), while were is for the first person plural (we were), the second person singular and plural (you were) and the third person plural (they were).
The present simple of the verb to be looks like this:
Forming Negations and Questions
I always tell my students that the verb to be is quite egotistical. It likes to do everything by itself.
This means that in order to build negative sentences in the present simple, you only have to add not after the verb forms:
I am not a student.
You are not (aren’t) from Poland.
He/She/It is not (isn’t) from Argentina.
We are not (aren’t) ready.
You are not (aren’t) my parents.
They are not (aren’t) doctors.
The Past Simple: How Things Were Before
The past simple of to be is very simple:
Use of is,am,are