Conditionals where consequences take place before conditions

Question

How do I express the thought that the occurrence of some event results in the occurrence of another before it.. in other words, that if an event were to happen, some other event would happen before it?

I would say:

If A were to happen, B would happen before it.

or:

If A would happen, B would happen.

or:

If A happened, B would have happened.

In the second example, I used would because I read this on Grammarly:

An if- or when-clause (often used to form conditional sentences) generally does not contain “will,” which is the simple future tense of the verb “to be.” One exception is when the action in the if- or when-clause takes place after that in the main clause. For example, consider the following sentence: If aspirin will ease my headache, I will take a couple tonight instead of this horrible medicine.

and this from wikipedia:

Also, in cases where the event of the if-clause follows that of the main clause, use of would in the if-clause is standard usage (this is similar to the aspirin example given above for will):

If it would make Bill happy, I would give him the money.

And from my understanding, I think that the last example only describes or talks about the present, it doesn't say anything about the future. The result clause concerns the past of the moment of speaking, no more, and the condition concerns one case or instance whose result took place already in the past.

Do the examples express that thought? Also, does the following express that thought?:

If A will happen, B will happen before it.

Answer 1

Usually effects come after causes, not before. So you're asking about cases where one of two things is true. (1) The consequent isn't actually a consequence, but something else like a precondition or an inference. (2) You're considering a causal relationship that runs backwards in time (because someone has a time machine, or the ability to foresee the future, or our world is being played with by gods or extradimensional superbeings, or something like that).

In case 1, there will often be wording that does a better job of explaining what the relation is between antecedent and consequent. For instance: "If you travel abroad, you must first have acquired a passport": the relationship is that you aren't allowed to do X without having done Y. Or "If you open that box and find a golden key inside it, then the princess must have put that key in the box last week": the relationship is that the only way X would happen is if Y had happened first.

That's with "If X happens" rather than your "If X were to happen" or "If X happened". I think that with those phrasings I would expect something more involved. "If you were to travel abroad, you would necessarily already have acquired a passport."; "If you were to open that box and find a golden key inside it, then the princess would have to have put that key in the box last week."

In case 2, I wouldn't necessarily expect any way of phrasing it to sound quite right, because it's describing an extremely unusual situation (quite possibly one that has never occurred and never will). Maybe "If you open that door, then last week the wizard will have seen you do it and have placed the dragon on the other side of the door."?

The specific phrasings you asked about:

I don't think I'd ever say or write "If X were to happen then Y would happen first"; it's not wrong exactly but it would feel very strange. Maybe if Y were still in the future (even though earlier than X).

I don't think I'd ever use "If X would happen" if I were just describing future possibilities -- it's too much like a common idiom for asking people to do things. ("If you would be so kind as to open the door...?")

I think "If X happened, Y would have happened" is OK. I think such sentences are generally clearer with some word like "already" or "first" clarifying that Y really is earlier than X. I'd generally avoid them in favour of things like "If X happens" or "If X were to happen", just because it feels a bit weird to use "happened" about something in the future.

To me, "If X will happen ..." feels strange in the same sort of way as "If X would happen" does. I'd say "If X happens" or "If X were to happen" or maybe "If X happened" rather than "If X will happen". Again, "If X will happen" feels too much like you're making a request rather than just speculating about the future. "If you will step this way, you'll find a special surprise I've prepared for you" isn't just a prediction, it's an invitation.