This Tense is used to express an action which is over or completed at some point of time in the past. In this tense the second form of the verb is used.
The formula for simple past is Subject + V2
I ate an apple yesterday.
We ate apples yesterday.
We ate apples yesterday.
You ate an apple yesterday.
He ate an apple yesterday.
She ate an apple yesterday.
It ate an apple yesterday.
They ate apples yesterday.