The use of English and French past tenses does not follow the same logic. Therefore, it might be useful to stop for just a moment and to think about the different situations that can be expressed in the past and how they are expressed in English.
One is that things happen at the same time, English uses the progressive tense.
He was sitting in a bar, drinking a coffee and reading the newspaper.
Things happen in succession: English uses the simple past:
He came to the bar, ordered a beer and went home without paying.
Things happened in the past and still have an impact on the present; English uses present perfect:
He has worked on this project for more than two years.
An action started in the past and is ongoing; English uses present perfect continuous. (If a distinction is to be made between an action that has an impact on the present of the speaker but is finished and an ongoing action, in roman languages we need a completely different structure.)
I have been working on it the whole day, but I am not done.
Things happened in the past before another event started; English uses past perfect:
He had long gone to bed, before she came home.
As you might have guessed, the same situations are to be expressed in French, life is not so different there... However, other tenses are used, as we will now see.