past perfect vs. continous

[Lazarus]

*Both situations happened in the past and have no inluence*

Can we say something like this:

Since Paul joined the band, they had been gradually going downhill. It's good they called it quits.
Or should it be:

After Paul had joined the band, they were gradually going downkill. It's good they called it quits.

 

[GenJen54]

Neither really works because the progressive is out of place.

Think of a time line. Action One happens in a past before Action 2. Both actions happened or have been happening in a time frame leading to now (the present).

Since Paul joined the band (action 1 - cause), they have been gradually going downhill (effect - they started going downhill after Paul joined the band.) It's good they called it quits.

Since Paul had joined (action 1 - causal) the band, they were gradually going (action 2 - result) downhill.

Before Paul joined the band (action 2), they had been (action 1) gradually been going downhill.

 

[comsci]

To summarize the above a bit, one would almost always use "past tense" along with "present perfect continuous" to describe an event happening from a past time up to present(and most likely still happening). You would then use "past tense" and "past perfect continuous" to describe an event that had been happening before a past time. For example a time zone of say two weeks ago up to last weekend.

As GenJen said, the key is to think of a time line and you would understand why these different tenses are used cooperatively to show/describe events that happen under different time zones.