Using the imperfect indicative vs. subjunctive with "si"

Question

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)?

Answer 1

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.)

Edit: Thank you, Alan, for your patience and for providing the English version.

On the basis of the English version:

"Was he imagining things? Could all this have anything to do with the Potters? If it did . . . if it got out that they were related to a pair of — well, he didn’t think he could bear it."

it is clear that "did" refers to the actual possibility of that situation having to do with the Potters, and "Si era así" conveys that idea precisely, as does "si se descubría".

Now, the translator chose to write "si así fuera", and I have to say it also sounds right, only rendering that possibility more remote. However, "si se descubriera" would sound, if not wrong, at least awkward, and that is because of the presence of "creía" and because "could" is more of a backshifted future than an actual conditional of the kind we have in present-time conditional sentences:

• If my neighbors were burglars, I don't think I could bear it / I couldn't bear it.

My point is that the conditional sentence both in English and Spanish expresses an actual possibility in the past rather than a hypothetical situation, it being possible to paraphrase it as: If it was the case that it did and it got out that they were related to a pair of — well, he didn’t think he could bear it.

Similarly, in Spanish we can use the imperfect indicative instead of the imperfect subjunctive to express a possible state of affairs in the past. Under these circumstances, I think only "fuera" could fit in there, while any other verb in the imperfect subjunctive would sound odd, my natural instinct as a native speaker being to use imperfect indicative for any verb other than "ser".

To further prove my point that the conditional sentence in question is set in the real past rather than in a hypothetical present or future where only the subjunctive is allowed, let 's imagine a condition with be in the third person singular:

• If Harry was (NOT were) a wizard, he didn't think he could bear it. (Si Harry era un brujo, no creía que podría/pudiera soportarlo.) -> This is clearly set in a real past, hence the impossibility to use "were".

Instead, if the conditional is set in a hypothetical present or future, "were" can be used in English, and "fuera" is required in Spanish:

• If Harry was/were a wizard, I don't think I could bear it. (Si Harry fuera un brujo, no creo que podría/pudiera soportarlo.)

Answer 2

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.

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After reading the comments, I think that it can be confusing (or at least counter intuitive) using a past tense (indicative imperfect or subjunctive imperfect) to talk about present or future hypothetical actions. Therefore, I think it's worth mentioning these things:

• If you get confuse, the tense of a conditional sentence is more easily deduced by the form of the verb in the main clause. As cited before, in Spanish, 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. For example: Si me tocara/tocase (indicative imperfect/imperfect) la lotería, me compraría (conditional) un coche. Note how the main clause (Me compraría un coche), is in conditional (clearly denoting a present or future hypothetical scenario).
• The use of tenses (like past imperfect) in situations where the temporality of the action doesn't match the verb tense is a phenomenon quite common in Languages (like English and French, for example). In Spanish it's called "uso desplazado (o dislocado) de los tiempos verbales". You can read more about it here and here. This is the reason why in Spanish and in French we have to use the past imperfect to talk about a present or future hypothesis (conditionnel présent) or why we can use the present to talk about past actions (Presente histórico | Présent historique | Historical present).
• If you really want to talk about past hypothetical actions, like Gustavson mistakenly argues you can do with the imperfect, you have to use the pretérito pluscuamperfecto or antepretérito de subjuntivo. For example: Si hubiera/hubiese terminado los estudios, hoy tendría un trabajo mejor. Again, this is a grammatical rule that you can check in the Diccionario Panhispánico de Dudas.