Apaga el televisor antes de dormir.

Apagar is the infinitive: “to turn off.”
Apaga is a command form (imperative) for informal “you” (tú).

In Spanish, most affirmative tú-commands use the 3rd person singular present form:

• él/ella/usted apaga → ¡Apaga! = Turn off!

So Apaga el televisor literally means “(You) turn off the TV set.”

The subject “you” is implied and not written.

Spanish usually omits subject pronouns because the verb ending shows who the subject is.

• Apaga → tells us it’s tú (informal singular “you”).

If you really wanted to include it (for emphasis or contrast), you could say:

• Tú apaga el televisor antes de dormir.

…but in normal speech you just say Apaga el televisor.

Use the formal usted command, which takes the subjunctive form:

• Apague el televisor antes de dormir.
  = Please turn off the TV before going to bed.

Apaga → informal (tú)
Apague → formal (usted)

For Latin America, you normally use ustedes for “you (all).” The command is:

• Apaguen el televisor antes de dormir.
  = Turn off the TV before going to bed, you guys / you all.

Forms:

• tú: Apaga
• usted: Apague
• ustedes: Apaguen

All three exist, but they’re not identical:

• el televisor = the TV set, the physical device.
• la televisión = television as a system or programming
  (e.g. “No hay nada en la televisión” = “There’s nothing on TV.”)
• la tele = very common colloquial word for both the device and the programming, like “the TV.”

In many places in Latin America you will also hear:

• Apaga la tele antes de dormir.

Using el televisor is just a bit more “standard” or neutral, emphasizing the device.

No, that sounds wrong in Spanish.

With singular countable nouns like this, you almost always need the definite article:

• ✅ Apaga el televisor.
• ❌ Apaga televisor.

The article el is required, similar to saying “Turn off the television” in English.

All three are common with lights and electronic devices:

• apagar = to turn off / switch off
• prender = to turn on / switch on (very common in Latin America)
• encender = to turn on / switch on (a bit more formal/neutral; understood everywhere)

Examples:

• Apaga el televisor. = Turn off the TV.
• Prende / Enciende el televisor. = Turn on the TV.

In some regions, one verb may sound more natural than the other, but apagar is standard everywhere.

In Spanish, “before doing something” is expressed as:

• antes de + infinitive

So you must say:

• ✅ antes de dormir = before sleeping / before going to sleep
• ❌ antes dormir

The de is required after antes when it’s followed by a verb in the infinitive.

Here dormir is an infinitive used as a general action: “before sleeping.”

1. dormir (infinitive)

   • antes de dormir = before sleeping / before going to sleep (in general)

2. dormirse (reflexive infinitive)

   • antes de dormirse = before falling asleep (focused more on the moment you actually fall asleep).
     In practice, antes de dormir is more common and perfectly natural.

3. te duermas (subjunctive, “you sleep/fall asleep”)

   • This would appear in a different structure: antes de que te duermas
     (see next question).

In everyday speech, antes de dormir is simple, natural, and widely used.

Yes, you can say:

• Apaga el televisor antes de que duermas.

Difference:

• antes de dormir

  • Uses an infinitive
  • Feels a bit more general and neutral
  • Literally: before sleeping

• antes de que duermas

  • Uses a subordinate clause with subjunctive (duermas)
  • Feels a little more specific and personal (before you sleep)
  • Slightly more formal/structured

In everyday conversation, antes de dormir is more common and perfectly fine.

You can add a direct object pronoun for “it” (masculine singular → lo):

• ¡Apágalo antes de dormir! = Turn it off before sleeping.

Rules for affirmative commands with pronouns:

• Pronouns attach to the end of the verb:
  • apaga + lo → apágalo
• An accent is added to keep the original stress:
  • apaga (stress on pa) → apágalo (stress stays on pa)

With a formal command:

• Apáguelo antes de dormir. (usted)

Yes. That’s completely correct and very natural:

• Antes de dormir, apaga el televisor.
• Apaga el televisor antes de dormir.

Both mean the same thing. Moving “antes de dormir” to the front just changes the rhythm, not the meaning.

Yes, televisor is a normal countable noun:

• singular: el televisor = the TV (set)
• plural: los televisores = the TVs (sets)

Command examples:

• Apaga el televisor. = Turn off the TV.
• Apaguen los televisores. = Turn off the TVs. (you all)