Learn Hardcore Spanish (Spain): Por la noche se rompió la bombilla y usamos una linterna eléctrica hasta encontrar el interruptor. - At night the light bulb broke and we used an electric flashlight until we found the switch.

por la noche = during the night / at night (general time frame, not a specific night)
en la noche is possible in some varieties of Spanish, but in Spain it is much less common and often sounds Latin American or unusual in everyday speech.
You can also say de noche, which is very common and also means “at night” in a general way.

In Spain, for “at night” people typically say:

por la noche
de noche

So por la noche here is the most natural, standard Peninsular choice.

What is the role of se in se rompió la bombilla?

Se in se rompió la bombilla is not really “reflexive” in the sense of “it broke itself”. It’s what’s often called:

middle voice / anticausative: something breaks without saying who broke it.
Very similar in meaning to English “the bulb broke” or “the bulb went out / got broken”.

Compare:

Rompimos la bombilla. = We broke the bulb. (someone did it)
La bombilla se rompió. = The bulb broke. (focus on the result; cause/agent not expressed)

So se rompió la bombilla means “the bulb broke”, and se helps to form this kind of “it broke (on its own / somehow)” structure.

Is there any difference between se rompió la bombilla and la bombilla se rompió?

Both are grammatically correct and mean essentially the same:

Se rompió la bombilla.
La bombilla se rompió.

Differences:

La bombilla se rompió sounds a bit more neutral and is probably what you’ll hear slightly more often.
Se rompió la bombilla can sound a bit more “event-focused” (something broke – it was the bulb) and is very common in storytelling or when you’re emphasizing the event rather than the bulb itself.

In everyday speech in Spain, people use both orders freely. The difference is subtle and mostly about emphasis, not meaning.

Why is rompió in the past simple (pretérito) and not rompía?

Rompió is the preterite (pretérito indefinido), used for completed events in the past.

(Por la noche) se rompió la bombilla = The bulb broke (at a specific time).

If you used se rompía, that would be the imperfect (rompía), which suggests an ongoing/repeated background action:

Se rompía la bombilla would sound like The bulb kept breaking / was in the process of breaking, which doesn’t fit a single, sudden event.

Here, the breaking is a single, completed incident, so se rompió (preterite) is the natural choice.

How do I know that usamos here means “we used” (past), not “we use” (present)?

The form usamos is the same in the present and in the preterite for nosotros:

(Presente) Nosotros usamos la linterna. = We use the flashlight.
(Pretérito) Anoche usamos la linterna. = Last night we used the flashlight.

You know it’s past here because:

The previous verb se rompió is clearly past (preterite).
The time expression por la noche also points to a past narrative.
The whole sentence describes a sequence of past events.

Spanish often relies on context to distinguish between present and past in forms like usamos, hablamos, vivimos, etc.

Why is hasta encontrar el interruptor using the infinitive encontrar instead of a conjugated verb?

In Spanish, hasta + infinitive is a very common structure meaning “until doing X”:

Usamos una linterna eléctrica hasta encontrar el interruptor.
= We used a flashlight until (we) found the switch.

Key points:

The subject of encontrar is the same as the main verb (usamos → “we”), so Spanish can drop the subject and use the infinitive.
You could also say:
…hasta que encontramos el interruptor. (with a conjugated verb)

Both are correct:

hasta encontrar el interruptor
hasta que encontramos el interruptor

The version with the infinitive is a bit shorter and very natural in narration.

Could I say hasta que encontramos el interruptor instead of hasta encontrar el interruptor? Is there any difference?

Yes, you can:

…y usamos una linterna eléctrica hasta encontrar el interruptor.
…y usamos una linterna eléctrica hasta que encontramos el interruptor.

Both are correct and mean “until we found the switch.”

Nuance:

hasta + infinitive (hasta encontrar) is slightly more compact and often a bit more neutral/formal in writing.
hasta que + conjugated verb (hasta que encontramos) sounds very natural in speech and makes the subject of the second action more explicit (though in this case it’s obvious).

In everyday spoken Spanish in Spain, you will hear both structures frequently.

What exactly is a linterna eléctrica? Is this just a flashlight, and is this how people in Spain really say it?

Yes, una linterna eléctrica is a flashlight (BrE: torch).

In current Peninsular Spanish:

The normal everyday word is simply linterna.
eléctrica is technically correct (distinguishing it from, say, an oil lamp), but in everyday speech many people just say linterna unless they need to be extra clear.

So in Spain people would usually say:

Usamos una linterna = We used a flashlight / torch.

The phrase linterna eléctrica sounds slightly more formal, old-fashioned, or textbook-like, but is still understandable and correct.

Why is it una linterna eléctrica and eléctrica ends in -a?

Because adjectives in Spanish agree in gender and number with the noun they modify.

linterna is feminine singular → una linterna
The adjective eléctrico / eléctrica must match that:
- masculine: eléctrico
- feminine: eléctrica

So:

un aparato eléctrico (masculine)
una linterna eléctrica (feminine)

That’s why it’s eléctrica, not eléctrico.

What does interruptor mean here, and is this the normal word for “light switch” in Spain?

Interruptor means switch, especially an electrical switch. In a home context, in Spain it typically means a light switch.

So el interruptor in this sentence is understood as “the light switch” (the one you were trying to find in the dark).

Common related words in Spain:

interruptor (de la luz) = light switch
enchufe = electrical socket, plug outlet
regleta = power strip
botón = button (not usually used for a wall light switch)

So yes, interruptor is the normal, standard word in Spain for the light switch.