Present Of To Be

 

Básicamente el verbo TO BE significa SER o ESTAR de acuerdo al contexto donde se emplee. Sus formas para el Simple Present se reducen a tres que son  AM, ARE y IS , y para el Simple Past, a dos: WAS y WERE, usandose con los pronombres de la conjugación de la siguiente forma:

                                   You                                             He

 I  AM / WAS               We     ARE / WERE                  She        IS / WAS

                                    They                                          It

 

I am a student.
He is a teacher.
She is a journalist.
It is a book.
We are mechanics.
You are pilots.
They are policemen.


https://www.eclecticenglish.com/grammar/PresentSimpleToBe1A.html