1. Action finished in the past (single or repeated)
I visited Berlin last week.
Andrew watched TV yesterday.
My friends went to Paris a week ago.
My parents ate a lot of junk food when they were young.
2.. series of completed actions in the past
First I got up, then I had breakfast.
On Sunday my brother and me went to a nice lake. There we met our friends. We swam in the warm water and played volleyball in the afternoon. Too bad that we had to go home in the evening. We didn't want to go to school on Monday.
3. together with the Past Progressive/Continuous – the Simple Past interrupted an action which was in progress in the past.
They were playing cards when the telephone rang.
1st action → Past Progressive → were playing
2nd action → Simple Past → rang
While Dennis was reading outside, it started to rain.
1st action → Past Progressive → was reading
2nd action → Simple Past → started
Taken from: https://www.englisch-hilfen.de/en/grammar/simple_past_use.htm
The simple past is used principally to describe events in the past.
The affirmative form:
I was in London in 1999.
Pam was in London in 1999, too.
We were together.
She was my girlfriend.
The interrogative form:
Were you in London last year?
Was Pam with you?
Were you together?
The negative form:
I wasn't in Paris in 1999.
Pam wasn't in Paris in 1999.
We weren't in Paris.
emember:
1. wasn't is the short form of was not. You can say either:
I was not in Paris, or
I wasn't in Paris.
2. weren't is the short form of were not. You can say either:
we were not in Paris, or
we weren't in Paris.