Learn Hardcore Spanish (Latin America): Mi hermano se queda dormido en el sillón después de la cena. - My brother falls asleep on the armchair after dinner.

Mi hermano duerme en el sillón = My brother sleeps on the armchair (describes the state of sleeping there).
Mi hermano se queda dormido en el sillón = My brother (ends up) falling asleep on the armchair (focus on the moment or result of falling asleep, often without planning to).

So se queda dormido emphasizes the process/result of falling asleep, not just the state of being asleep.

What is the role of se in se queda dormido?

Se is a reflexive pronoun here, and quedarse dormido is used as a pronominal verb (verb that is naturally used with a reflexive pronoun).

quedar on its own often means to remain, to be left, to arrange to meet.
quedarse dormido means to fall asleep / to end up asleep.

You normally cannot drop se here:

✅ Mi hermano se queda dormido.
❌ Mi hermano queda dormido. (sounds wrong or very unnatural in everyday speech)

So in this expression, se is part of the standard structure that gives quedar the meaning to end up/fall (into a state).

What is the difference between se queda dormido and se duerme?

Both can be translated as he falls asleep, but:

se duerme (from dormirse)
- More neutral: simply he falls asleep.
- Focus on the action of going from awake → asleep.
- Common and very standard.
se queda dormido (from quedarse dormido)
- Often implies he nods off / he ends up asleep, sometimes unintentionally.
- Slight nuance of ending up in that state, often because he’s tired or relaxed.

In many everyday contexts, both are possible:

Mi hermano se duerme en el sillón después de la cena.
Mi hermano se queda dormido en el sillón después de la cena.

The original version paints a slightly stronger picture of “dozing off” rather than just “going to bed to sleep.”

Why is it dormido and not another form like dormida or durmiendo?

Dormido is a past participle functioning as an adjective, and it has to agree in gender and number with the subject:

Mi hermano se queda dormido. (brother → masculine singular)
Mi hermana se queda dormida. (sister → feminine singular)
Mis hermanos se quedan dormidos. (brothers / mixed group)
Mis hermanas se quedan dormidas. (sisters)

You can’t use durmiendo here:

durmiendo is a gerund (like sleeping), and quedarse durmiendo would mean something more like to remain sleeping or to stay asleep, not to fall asleep.

So:

quedarse dormido = to fall asleep / to drift off.
quedarse durmiendo = to remain in the state of sleeping (different idea).

What is the difference between sillón and sofá?

In Latin American Spanish:

sillón usually means an armchair: a large, comfortable chair for one person, often with arms.
sofá means a sofa / couch: a longer piece of furniture for 2+ people.

So:

en el sillón = on the armchair.
en el sofá = on the sofa / couch.

You would choose whichever matches the furniture you’re talking about. The sentence specifically imagines him nodding off in an armchair.

Why is it en el sillón and not sobre el sillón?

Both en and sobre can sometimes be translated as on, but:

en is the default preposition for locations and can mean in, on, or at depending on context.
sobre more literally means on top of, over and can sound a bit more physical or literal.

For objects you sit or lie on (chairs, sofas, beds), en is by far the most common:

en la cama (in/on the bed)
en la silla (on the chair)
en el sofá / sillón (on the sofa / armchair)

Sobre el sillón is not wrong grammatically, but in normal speech en el sillón is what you’d hear.

Why do we say después de la cena and not just después la cena?

When después is followed by a noun, you must put de:

✅ después de la cena = after dinner.
❌ después la cena

Después can work two ways:

Adverb (on its own)
- Cenamos y después vemos la tele.
  We eat dinner and after(wards) we watch TV.
Preposition (before a noun)
- después de la cena (after dinner)
- después de la película (after the movie)

As a preposition, it always needs de.

Why is there a la in la cena? Could you say después de cena?

In this structure, you normally use the definite article la:

✅ después de la cena = after (the) dinner.

Después de cena is not standard in most dialects and usually sounds wrong. With meals, Spanish often uses the article:

la cena – dinner
el desayuno – breakfast
el almuerzo / la comida – lunch/main meal (varies by country)

So:

Después de la cena, mi hermano se queda dormido.

You can avoid the article by changing the structure:

Después de cenar, mi hermano se queda dormido.
(After having dinner / After eating dinner, my brother falls asleep.)

Here cenar is a verb (infinitive), so no article is needed.

Can I say después de cenar instead of después de la cena? Is there a difference?

Yes, you can, and both are very natural:

Después de la cena, mi hermano se queda dormido en el sillón.
After dinner, my brother falls asleep on the armchair.
Después de cenar, mi hermano se queda dormido en el sillón.
After eating dinner, my brother falls asleep on the armchair.

Nuance:

después de la cena focuses slightly more on the event / time of dinner.
después de cenar focuses slightly more on the action of eating dinner.

In practice, they’re almost interchangeable in everyday speech.

What tense is se queda and what does it imply about time (now vs habit)?

Se queda is present indicative (3rd person singular of quedarse).

In Spanish, the simple present can express:

A general habit
- Mi hermano se queda dormido en el sillón después de la cena.
  → He usually or often falls asleep on the armchair after dinner.
Something happening right now, if the context makes that clear
- If you’re watching him do it as you speak, it could also mean he’s falling asleep right now.

Unlike English, Spanish doesn’t always need a separate “-ing” form (is falling) to talk about current actions; the simple present is more flexible.

If the subject were my sister or my siblings, how would the sentence change?

You need to adjust hermano / se queda / dormido to match gender and number:

My sister
- Mi hermana se queda dormida en el sillón después de la cena.
My siblings (mixed group or only brothers)
- Mis hermanos se quedan dormidos en el sillón después de la cena.
My sisters (all female)
- Mis hermanas se quedan dormidas en el sillón después de la cena.

Changes:

mi → mis for plural.
hermano → hermana / hermanos / hermanas.
se queda → se quedan (plural verb).
dormido → dormida / dormidos / dormidas (agreement with the subject).

Could I drop mi hermano and just say Se queda dormido en el sillón después de la cena?

Grammatically, yes: Se queda dormido en el sillón después de la cena is a complete sentence in Spanish.

However:

In the third person (he/she/they), if you remove the subject (mi hermano), the listener must already know who you’re talking about from context.
Spanish often omits subject pronouns (yo, tú, él, etc.), but nouns like mi hermano are included or omitted depending on clarity.

If the conversation is clearly about your brother, you can drop it:

—¿Qué hace tu hermano después de la cena?
—Se queda dormido en el sillón.

Is quedarse dormido specific to Latin America, or is it also used in Spain?

Quedarse dormido is standard in both Latin America and Spain. It’s a very common, neutral expression in the whole Spanish-speaking world.

In Latin America and Spain you will hear:

Me quedé dormido en el sofá. – I fell asleep on the couch.
Siempre se queda dormida viendo la tele. – She always falls asleep watching TV.

So this is not region-specific; it’s broadly understood and used.

Does cena always mean “dinner” in Latin America, or can it mean lunch?

In most of Latin America:

la cena = the evening meal → dinner / supper.
el almuerzo or la comida varies by country, but typically refers to the midday meal (lunch or main meal).

So in this sentence, después de la cena is clearly after the evening meal, not lunch.