Is it true that when we use 'before' with the Past Perfect tense, the action in the past simple happens first?

Question

I've stumbled across the following rule in the grammar book 'My Grammar Lab': with before + past perfect the action in the past simple happens first. The following example has been given: I left university before I'd finished the course. In this very book I've also found the following sentence 'All the leaves had fallen from the trees before we arrived', which doesn't follow this rule.

I've also found these two sentences in the Cambridge dictionary:

1. Before I had a chance to thank him, he’d gone.
2. Before he had finished his training, he was sacked.

In the first sentence the past perfect tense has been used for the earlier action and in the second sentence the past simple tense has been used for the earlier action.

As far as I know, we usually use the past perfect for the earlier action and the past simple for the later one, so I'm really confused about the correct way of using 'before' with the past perfect tense.

Could you please tell me if there is a clear rule regarding this case?

Thank you in advance.

Answer 1

Your book is correct. You've misunderstood the application of the rule.

The structure here is [ "before" + past perfect ], and presumably there is also a main clause in the simple past. This means "before" must come directly before the past perfect clause and subordinate it.

You give two examples where you believe the rule has been violated, but neither of those sentences has the structure [ "before" + past perfect ]:

All the leaves had fallen from the trees before we arrived
Before I had a chance to thank him, he’d gone.

Both sentences have the structure [ "before" + simple past ], so this rule does not apply here at all.

The general rule that always applies with "before" is this: if you have two clauses, and one of them is subordinated by "before", the other one always happens first. Where there's an apparent conflict, the word "before" takes priority over the verb tenses.

Answer 2

Both of these sentences would sound equally good with a simple past in place of the past perfect.

Furthermore, changing them in that way would have no effect on the sequence of events. What it would do (what using the past perfect almost always does) would be to set a temporal focus at some later point in the past.

So Before I had a chance to thank him, he went does not set any particular temporal focus. But Before I had a chance to thank him, he had gone does: it invites the hearer/reader to place themselves mentally at a time when the speaker/writer realised that he had gone: it may thus make the narrative more immediate, or draw the reader/hearer into it more.

Similarly with the second sentence, Before he finished his training he was sacked does not set a temporal focus, so reads as more detached from the events narrated. Before he had finished his training he was sacked sets a focus within the sequence of events, and again makes the narrative more immediate.

You could use past perfect in both halves in either case:

Before I had had a chance to thank him, he'd gone.

I don't think this adds anything to the original, because the focus is already set, and we tend not to use the past perfect when the temporal relationships and focus are already made clear; but it reads perfectly well.

Before he had finished his training, he had been sacked.

This is also possible, but changes the meaning, because it is setting a later temporal focus and looking back on the sacking from then.