Past Perfect Simple

Past Prefect Simple is a tense that describes situation or activity that was completed before another past situation or activity .

Example : Aria had already gone to Lea when my mom arrived .

In this situation two events that both happened at the past .

Aria went to lea & mom arrived .

Aria going home happened and was completed before mom arriving home , that’s why we used Past Perfect Simple .

For the first action we use Present Perfect Simple and for the second action we use Past Simple .