Hello,
I want to know when I have to use simple past instead of present perfect or even past perfect when I’m talking.This is a serious issue for me.
Yo could Google it. This page explains the difference in a concise manner:
web2.uvcs.uvic.ca/elc/StudyZone/ … pvpast.htm
This one also has exercises:
ego4u.com/en/cram-up/grammar/simpas-preper