A. We use the Past Simple we are talking about past events and situations:
a. talking about an event that happened at a particular time in the past. (e.g. We arrived home before dark.)
b. talking about something that continued for some time in the past. (e.g. Everybody worked hard through the winter.)
c. talking about something that happened several times in the past, we use the Past Simple or 'use to' or 'would' (e.g. Most evenings we stayed at home and watched DVDs. or Most evenings we used to stay at home and watch DVDs. or Most evenings he would take the dog for a walk.) But we do not normally use 'would' with stative verbs (be or know).
A1. We use the Past Continuous when we are talking about something which happened before and after a given time in the past: (e.g. It was just after ten. I was watching the news on TV) and when we are talking about something happening before and after another action in the past. (e.g. He broke his leg when he was playing rugby.)
A2. When we are looking back from a point in the past to something earlier in the past (the past in the past) we use the Past Perfect. (e.g. Helen suddenly remembered she had left her keys in the car.)
A3. when we are talking about the effects in the present of something that happened in the past, we use the Present Perfect (e.g. I can’t open the door. I’ve left my keys in the car.) and when we are talking about something that started in the past and still goes on. (e.g. We have lived here since 2007. (and we still live here))
Idiom 365
Don't count your chickens before they hatch: should not make any plans that depend on something good happening until a good thing has really happened
Example: Don’t count your chickens before they hatch! We haven’t even submitted our proposal yet!