We use the past tense to talk about:
something that happened once in the past:
I met my wife in 1983.
We went to Spain for our holidays.
They got home very late last night.
something that happened several times in the past:
When I was a boy, I walked a mile to school every day.
We swam a lot while we were on holiday.
They always enjoyed visiting their friends.
something that was true for some time in the past:
I lived abroad for ten years.
He enjoyed being a student.
She played a lot of tennis when she was younger.
we often use expressions with ago with the past simple:
I met my wife a long time ago.
We can use the past perfect to show the order of two past events. The past perfect shows the earlier action and the past simple shows the later action.
When the police arrived, the thief had escaped.
It doesn't matter in which order we say the two events. The following sentence has the same meaning.
The thief had escaped when the police arrived.
Note that if there's only a single event, we don't use the past perfect, even if it happened a long time ago.
The Romans spoke Latin. (NOT The Romans had spoken Latin.)
