Apaga la televisión; si no, no puedo concentrarme.

Apaga is the affirmative tú command of apagar.

• tú apagas = you turn off / you are turning off (statement)
• apaga = turn off (command, addressed to one person informally)
• apague = formal usted command

So Apaga la televisión means you are telling someone directly, informally: Turn off the television.

For most verbs, the affirmative tú command uses the third-person singular present form.

Examples:

• apagar → él/ella apaga → Apaga
• hablar → Habla
• come from comer
• vive from vivir

So:

• tú apagas → statement
• ¡Apaga! → command

Be careful: negative commands are different:

• No apagues la televisión.

Spanish often uses the definite article more naturally than English does.

So:

• Apaga la televisión = literally Turn off the television
• In natural English we often just say Turn off the TV

This does not necessarily mean a specific unusual television; it is simply standard Spanish usage. The same happens with many everyday objects:

• Cierra la puerta
• Abre la ventana
• Lava los platos

Yes. In everyday speech, la tele is very common and natural.

So you could say:

• Apaga la tele; si no, no puedo concentrarme.

Both are correct:

• la televisión = a bit fuller / more neutral
• la tele = more colloquial

In Spain, la tele is especially common.

This is a very common question.

In this sentence, si no is written as two words because it means if not:

• si = if
• no = not

So:

• Apaga la televisión; si no, no puedo concentrarme. = Turn off the television; if not, I can’t concentrate.

By contrast, sino as one word usually means but rather / except after a negative idea:

• No quiero té, sino café. = I don’t want tea, but rather coffee.

So here, si no is correct because it introduces a consequence: if you don’t.

Because Spanish normally puts no before the verb to make the sentence negative.

• puedo concentrarme = I can concentrate
• no puedo concentrarme = I can’t concentrate

So the sentence has:

• si no = if not
• no puedo = I can’t

These are doing different jobs:

1. si no introduces the condition
2. no puedo makes the main clause negative

Even though there are two nos, this is completely normal.

Because concentrarse is a reflexive verb in Spanish when it means to concentrate.

The full verb is:

• concentrarse = to concentrate

So:

• puedo concentrarme = I can concentrate
• literally: I can concentrate myself, though you should not translate it word for word

Other forms:

• me concentro = I concentrate
• te concentras = you concentrate
• se concentra = he/she concentrates

Many verbs in Spanish are reflexive where English is not.

Because after an infinitive, Spanish often attaches object or reflexive pronouns to the end.

Here:

• concentrar
  • me → concentrarme

After poder, you commonly use an infinitive:

• puedo concentrarme

You could think of it as:

• no puedo + concentrarme

This is completely standard.

Compare:

• Quiero sentarme.
• Necesito ducharme.
• Voy a acostarme.

With a conjugated reflexive verb, the pronoun goes before the verb:

• No me concentro.

Yes. No puedo concentrarme and no me puedo concentrar are both correct.

With verbs like poder + infinitive, the reflexive pronoun can often go:

• attached to the infinitive: puedo concentrarme
• before the conjugated verb: me puedo concentrar

So both are natural:

• No puedo concentrarme
• No me puedo concentrar

The meaning is essentially the same.

The semicolon links two closely related parts:

• Apaga la televisión
• si no, no puedo concentrarme

It works a bit like a strong comma or a softer full stop. It shows that the second part is directly connected to the first.

You may also see:

• Apaga la televisión. Si no, no puedo concentrarme.
• Apaga la televisión, si no, no puedo concentrarme.

The semicolon is stylistically neat here because the second clause expresses the consequence of the first not happening.

Yes, something is understood.

In full, the idea is roughly:

• si no apagas la televisión... = if you don’t turn off the television...

But Spanish often shortens this to simply:

• si no = if not / otherwise

This is very common and natural when the omitted action is obvious from context.

In standard Spain Spanish, it is approximately:

• te-le-bi-SYON in much of Spain, because c before i is pronounced like the th in thin
• IPA: /teleβiˈθjon/

A few notes:

• The stress is on the last syllable: -sión
• The written accent in televisión shows that stress
• The v in Spanish is not usually like a strong English v; it is softer, often between b and v

In Latin America, you would usually hear /telebiˈsjon/ with an s sound instead of the Spain th sound.

Concentrarme is stressed on -trar-:

• con-cen-TRAR-me
• IPA: /konθenˈtɾaɾme/ in much of Spain

A few pronunciation points for Spain:

• c before e in concen- is often the th sound of thin
• the r in -trar- is a tapped Spanish r
• the final me is unstressed

Because it ends in a vowel and has no written accent, it follows the normal stress rule, but the infinitive ending makes the stress pattern clear: concentrar → concentrarme.

Yes, absolutely. It sounds natural.

A few very natural variants are:

• Apaga la tele; si no, no puedo concentrarme.
• Apaga la televisión, que no puedo concentrarme.
• ¿Puedes apagar la tele? No puedo concentrarme.

The original sentence is perfectly normal and clear. It sounds like a direct request or command, probably said to someone nearby who has the TV on.

Not necessarily, but it is fairly direct.

In Spanish, commands are common and not always rude, especially with family, friends, or in situations where directness is normal. Still, tone and context matter.

More polite alternatives:

• Apaga la televisión, por favor.
• ¿Puedes apagar la televisión?
• ¿Te importa apagar la tele?

So the original sentence can sound:

• neutral
• firm
• slightly impatient

depending on tone of voice and situation.