was-were

When we want to use the verb to be in the past we use was or were dependent on pronouns:

I-was
You-were
He-was
She-was
It-was
They-were
we-were

These replace am, is and are:

Present-Past 
 
I am in Paris - I was in Paris
You are very fat - You were very fat 
He is my father - he was my father
They are small  - they were small


exercise: https://www.englisch-hilfen.de/en/exercises/tenses/was_were.htm