Gfyuki

I came across a sentence in Harry Potter y la piedra filosofal that has me a bit puzzled:

¿Se estaba imaginando cosas? ¿O podría todo aquello tener algo que ver
con los Potter? Si fuera así... si se descubría que ellos eran
parientes de unos... bueno, creía que no podría soportarlo.

I'm learning Spanish after having learned French, and I thought it was interesting that the si clauses in the French are a bit simpler:

Mr Dursley imaginait-il des choses ? Tout cela avait-il un lien avec
les Potter ? Si c’était le cas… S’il s’avérait qu’ils étaient parents
avec des… Non, il ne pourrait jamais le supporter.

How does one decide in Spanish whether to use the imperfect subjunctive (fuera) or the imperfect indicative (se descubría)?

You could also say:

• Si era así... si se descubría que ellos eran parientes de unos... bueno, creía que no podría soportarlo.

The imperfect indicative sounds more realistic, and is always past, while the imperfect subjunctive sounds more hypothetical and may point to the future.

What I don't like is "creía": I'd do away with it and write just "no podría soportarlo", but the original must have required the introduction of that verb of thinking.

Going back to your original sentence, let's see the two variants with their interpretations:

• Si era así, no podría soportarlo. (If it was --in fact-- like that, he wouldn't be able to cope with it).




• Si fuera así, no podría soportarlo. (Past meaning: If it happened to be like that, he wouldn't be able to cope with it / Present or future meaning: If it was/were like that, he wouldn't be able to cope with it.)

According to the Diccionario Panhispánico de Dudas (the "official" Spanish dictionary on frequent grammatical, lexical, and orthographical questions), you can use both the imperfect subjunctive (fuera) or the imperfect indicative (se descubría): they are interchangeable.

a) Si la condición se refiere al presente o al futuro, la prótasis va en pretérito imperfecto o copretérito de subjuntivo y la apódosis en condicional simple o pospretérito

Translation:

a) If the conditional sentence refers to hypothetical situations in the present or the future, the if clause must use the imperfect indicative or the imperfect subjunctive, and the main clause must use the conditional.

Therefore, I would disagree with Gustavson's answer. The use of the imperfect indicative or the imperfect subjunctive doesn't really matter. Both sentences would be semantically the same since both are expressing an hypothetical situations in the present or the future.