Past Tense

my friends, I'll explain about past tense ..
Past tense is to tell the event or incidents at past time.
Past tense is used
-When the speakers think of an activity or state as occured and complete at the specific time in the past.
-For a non fact in the present or future time. This is traditionally called the "subjective mood".
Example: if I had the money now, I'd buy a car
-To refer a single event on the past
Example: I called Mary last night
-The past habitual action
Example: we went to school together and we shared many experience