The past perfect tense when using time clauses

Question

I was taking a course about time clauses when I got confused about when I should use the Past perfect tense in the main clause.

According to the lesson, we should use Past Participle in the main clause when using these conjunctions : Before, Until, By the moment ; and it sounds logical when the time clause is of course in simple past. But according to the correction of the exercises in Interchange 3 book and some YouTube videos, I discovered that we can choose to not use the Past perfect tense when using "Before", and it will be still correct !

Could you explain to me how it's correct to not use the Past perfect tense even if the action in the main clause happened before the one in the time clause ?? In the example below, the correct answer for me is : "Before I got a job, I HAD BEEN completely broke".

Answer 1

You use past perfect when events were completed at the time of the narrative. Since these short phrase are not long enough to clearly establish a narrative time, there is room for ambiguity.

In a narrative there is the time of the narrative. The narrator describes events happening at a time in the past (in a past tense narrative). As one event follows another, the time of the narrative moves forward. But sometimes the narrator wants to talk about events that occurred before the time of the narrative, and for this the past perfect can be used.

There isn't a simple "if you use 'once' you must use past perfect" rule. The past perfect makes sense in longer narratives in which a clear narrative time is established.

Now in the first example, the time of the narrative is "when I was broke" the "before" phrase refers to some time after the time of the narrative. This is why the simple past is possible.

It would also be possible to use the past perfect, and this might be natural if a different time of the narrative had already been established.

There isn't enough context to clearly establish the time frame that is being discussed in the example, so there isn't a clear rule that can be applied.

Answer 2

Past Perfect time comes before the simple past time. So if some clause comes after a simple past time, it cannot use past perfect.

If a sentence has a time clause with "after", "once", "the moment" or "as soon as" with a simple past event, this means the main clause happens after it, so the main clause cannot use past perfect.

The moment I got a job, I moved into my own apartment.

If a sentence has a time clause with "before", "until" with a simple past event, the main clause happens before it, and the writer can choose between simple past and past perfect.

If the writer wants to connect the two events in the same simple past timeline, they can use simple past with both clauses. But if they want to separate the main clause into a different time before the simple past timeline, they can use past perfect to do that.

Before I found a job, I lived in my mother's basement. (same time period)
OR
Before I found a job, I had lived in my mother's basement. (different time periods)

In sentences with a time clause with "by the time", the main clause always has a perfect tense. That's just a rule of grammar, not a logical rule.

By the time I moved out, I had lived with my mother for eight years.
By the time I finish my PhD, I will have been in university for twelve years.