the past perfect after the simple past?

[Tukanja]

I've run across a sentence in a book dedicated to learners of English. Here it is.
1) We lit the fire last night but, unfortunately, it had gone out by this morning.

Here, the past perfect is used for an action happened after the other action happened in the simple past. As far as I am concerned, I think the past perfect is used in the latter clause due to the "by" preposition which makes the morning the newest simple past. Can we say, these two clauses are entirely independent so we can use the past perfect in the second one? Even if it is the case, I'm still confused with the fact that all of it can be used in the same sentence. Going out of the fire couldn't start before the fire was lit.

Please someone shed light on this.

Thanks

[mandrews]

Hi,

Treat the 2 parts of the sentence as 'independent'.

1) We lit the fire last night- fine, past simple
2) ...it had gone out by this morning. Past perfect is used as the speaker means 'by the time morning came/ by the time we looked at the fire it HAD GONE out'. So, 'by this morning' is the 'time marker' in the second part of the sentence; the fire went out BEFORE the morning came. Hope this helps.

[Tukanja]

3) We lit the fire last night but, by this morning, it had gone out.

If this word order is used, it seems more reasonable to me that I use the past perfect to mention the action that happened before the just mentioned other action or the definite past; is this correct thinking?

Also, please look at the sentence below

4) We lit the fire last night but it went out by this morning.

There are three simple pasts, specified in this sentence in the order in which they happened.
Would you consider 4) as grammatically unacceptable or at least as one with bad grammar comparing to 1)?

Thanks