Present Perfect Vs. Simple Past

žWe use the Past Simple tense to talk about a definite finished time in the past.

  Examples :
   I finished university three years ago.
   Where did we first meet?
   I didn't study French at school.

žWe use the Present Perfect tense for unspecified actions that occurred somewhere in

the past until now. It doesn’t matter when they happened. What is important is that they

happened.

  Examples:
   I haven't seen her today.
   Have you ever smoked a cigarette?
   I have never been abroad before.