# Routine or permanent situations
- use the simple form. For example, "I live in
"I lived in the countryside when I was a child" - this was a long-term situation in the past.
# Temporary or continuing situations
- use the continuous form. For example, "I'm working as a secretary at the moment" - the job isn't permanent and maybe I'm doing it for a while until I get another job.
"House prices are rising" - they are continuing to rise and haven't stopped rising yet.
"She was wearing a black dress" - she put it on before I saw her and she still wore it after I saw her - wearing the dress continued over a period of time.
# Connecting different times
- use the perfect form to show that one event was completed before another, or to show that one situation continues from one time to another.
For example, "I have lived here for two years" - I started to live here two years ago and I still live here.
"I will have finished the report before next week" - some time before next week, but I don't know exactly when.
Source : english-at-home