Learn Hardcore Spanish (Latin America): Apago la vela antes de dormir.

Apago la vela = I turn off the candle (the ending -o tells us it’s yo)
Yo apago la vela is also correct, but you usually add yo only for emphasis or contrast:
- Yo apago la vela, no tú. = I turn off the candle, not you.

So the sentence is natural without yo.

Why is it la vela and not just vela with no article?

In Spanish, countable nouns (like vela, mesa, libro) almost always need an article (definite or indefinite) or some determiner.

You cannot normally say: ✗ Apago vela.
You must say:
- Apago la vela. = I turn off the candle.
- Apago una vela. = I turn off a candle.

La vela suggests a specific candle that is known from context (for example, the one by your bed).

Could I say una vela instead of la vela? What’s the difference?

Yes, both are grammatically correct, but they feel different:

Apago la vela antes de dormir.
→ There is a particular, known candle (for example, the same one every night).
Apago una vela antes de dormir.
→ You turn off some candle, not necessarily a specific one. It sounds more indefinite or less specific.

In everyday use, if you mean your usual bedside candle, la vela is more natural.

Why is it antes de dormir and not antes dormir?

In Spanish, when antes is followed by a verb, you normally need antes de + infinitive.

Correct: antes de dormir = before sleeping / before going to sleep
Incorrect: ✗ antes dormir

Antes on its own can act as an adverb (no verb after it):

Apago la vela antes. = I turn off the candle beforehand.

But if you put a verb after antes, you must say antes de + [infinitive].

Why is it dormir and not duermo or me duermo?

After a preposition in Spanish (like de, para, sin, por), the verb must be in the infinitive.

antes de dormir = before sleeping
You cannot say: ✗ antes de duermo or ✗ antes de me duermo

Compare:

Duermo. = I sleep / I am sleeping. (main verb of the sentence)
Me duermo. = I fall asleep. (reflexive; the process of falling asleep)
Antes de dormir. = Before sleeping / before going to sleep. (verb after a preposition → infinitive)

So dormir is required because it comes after de.

Can I say antes de que duerma instead of antes de dormir?

Grammatically, both structures exist, but they are used in different situations:

Same subject → infinitive
- Apago la vela antes de dormir.
  The same person who turns off the candle is the one who sleeps. So Spanish prefers antes de + infinitive.
Different subject → antes de que + subjunctive
- Apago la vela antes de que él duerma.
  = I turn off the candle before he sleeps.
  Different subject (I vs he) → antes de que + subjunctive.

In your original sentence, the subject is the same (I turn off / I sleep), so antes de dormir is the natural and standard form.

Could I say antes de dormirme or antes de irme a dormir? Do they mean the same?

Yes, they’re possible, but the nuance changes slightly:

Antes de dormir
- Neutral and very common: before sleeping / before going to sleep.
Antes de dormirme
- Emphasizes the moment of falling asleep (reflexive me).
- Sounds like: before I actually fall asleep.
Antes de irme a dormir
- Literally: before I go to bed / before I go to sleep.
- Slightly more informal/colloquial; often used in conversation.

All three are natural in Latin American Spanish. Antes de dormir is the simplest and most general.

Can I change the word order and say Antes de dormir, apago la vela?

Yes. Both are correct:

Apago la vela antes de dormir.
Antes de dormir, apago la vela.

The meaning is the same. Moving antes de dormir to the beginning just changes the focus a bit and sounds slightly more narrative or stylistic, but it’s completely natural.

Could I replace la vela with la luz? Is that more common?

That depends on what you really mean:

Apago la vela antes de dormir.
→ You literally have a candle and you put it out.
Apago la luz antes de dormir.
→ You turn off the light (lamp, ceiling light, etc.). This is what most people do in real life.

So grammatically, both work. In modern life, apago la luz is more common; apago la vela is used if you really mean a candle or you’re speaking poetically or describing a specific situation.

Can I use a direct object pronoun and say La apago antes de dormir?

Yes. That is also correct.

Apago la vela antes de dormir.
→ Full noun is expressed: “I turn off the candle before sleeping.”
La apago antes de dormir.
→ La is the direct object pronoun replacing la vela (“I turn it off before sleeping”).

You typically use la apago when the object (the candle) is already known from context and you don’t need to repeat la vela.

Does apagar always mean “to turn off”? Can I use it for electronics and lights too?

Yes. Apagar is the standard verb for turning off / switching off / putting out many things:

apagar la luz = turn off the light
apagar la televisión = turn off the TV
apagar el teléfono = turn off the phone
apagar el fuego / la vela = put out the fire / candle

So the verb apagar is very general and is used with lights, devices, and flames.

Is this sentence specifically “Latin American Spanish,” or would it sound different in Spain?

Apago la vela antes de dormir is perfectly natural in both Latin America and Spain.

There is no regional difference in:

the verb form apago
the expression antes de dormir
the vocabulary vela (candle)

So you can use this exact sentence anywhere in the Spanish‑speaking world.