simple past

use it

With the simple past we make clear that what we say
is finished,
it is over,
it is not true anymore.

I phoned him yesterday morning.
Last week you painted the wrong door.
He arrived last Monday.
We knocked at the door but she didn't hear us.

In many sentences there are clues that tell you:
use the simple past

Words like:

yesterday, last month (week, year...),
two days (a week, some time...) ago,
in 2010