The timelines of the present perfect and the past perfect
How is the past time involved in these tenses?
When we refer to past actions that happened at an indefinite time, the present perfect is the right choice.
He has written several movie scripts.
With this, the action starts in the past but somehow extends up to the present. It might be because that event is unfinished, or that it may be relevant to the present time.
I have lived in Rome for 10 years now.
(I’m still living in Rome)
And what about the past perfect?
We use it when talking about a past action that’s finished before a certain time or before another past action. In other words, an action or actions happening before another.
I had lived in Italy for 10 years before moving to London.
(Meaning: after ten years, I moved to London)