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

my

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

• en: on
• el hermano: the brother

Questions & Answers about Mi hermano se queda dormido en el sillón después de la cena.

Why does the sentence use se queda dormido instead of just duerme?

Because quedarse dormido means to fall asleep / to drift off / to nod off, usually somewhat unintentionally or as a result of being tired.

• 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).