Learn Hardcore Spanish (Spain): Ambos padres se quedaron en casa porque hacía frío y llovía. - Both parents stayed at home because it was cold and raining.

Because quedarse means “to stay/remain,” while quedar (without the reflexive pronoun) often means “to arrange to meet,” “to be left,” or “to suit/fit.”

Se quedaron en casa = They stayed at home.
Quedaron en casa = They arranged to meet at home (different meaning).

What does the se in se quedaron do?

It’s the reflexive (pronominal) pronoun required by quedarse to mean “to stay.” It agrees with the subject:

Yo: me quedé
Tú: te quedaste
Él/ella/usted: se quedó
Nosotros: nos quedamos
Vosotros (Spain): os quedasteis
Ellos/ustedes: se quedaron

Why are hacía and llovía in the imperfect instead of preterite (hizo, llovió)?

Imperfect describes background conditions or ongoing states in the past. Cold and rain here are the ongoing circumstances that explain the completed action (se quedaron, preterite).

Preterite: completed event (they stayed).
Imperfect: background (it was cold, it was raining).

Could I say estaba lloviendo or llovía? Is there a difference?

Both are correct.

Llovía (imperfect) presents rain as background, general ongoing.
Estaba lloviendo (past progressive) highlights the ongoing process at that moment. In this sentence, either works; the nuance is minimal.

Why hacía frío and not estaba frío?

Spanish typically uses hacer for weather: hace frío, hacía frío, hará frío.

Está frío describes an object/person being cold to the touch or temperature (e.g., “The soup is cold” = La sopa está fría).
Feeling cold is tener frío: “I’m cold” = Tengo frío.

What’s the difference between porque, por qué, porqué, and por que?

porque = because (conjunction): Vinieron porque llovía.
por qué = why (question): ¿Por qué no salieron?
el porqué = the reason (noun): No explicó el porqué.
por que = “for which/that,” occurs with a preposition + relative pronoun: Este es el motivo por que te llamé (formal; often replaced by “por el que”).

Why is it en casa and not en la casa?

En casa means “at home” (no article). Use en la casa when you mean “in the house” (a specific house as a location, not necessarily one’s home).

Location at home: Se quedaron en casa.
Specific building: Se quedaron en la casa de la esquina.

Can I say a casa instead of en casa?

Use a casa for movement (to home), and en casa for location (at home).

Movement: Fueron a casa.
Location: Se quedaron en casa.

Does padres mean “parents” or “fathers”?

In everyday Spanish, padres means “parents.” If you specifically mean “fathers,” you must clarify (e.g., padres varones). Here, Ambos padres = “Both parents.”

Is ambos padres the same as los dos padres? Which sounds more natural?

They mean the same.

Ambos padres is a bit more formal or written.
Los dos padres is very common in everyday speech. For feminine nouns, use ambas: ambas hijas.

Can I move the cause to the front: Porque hacía frío y llovía, ambos padres se quedaron en casa?

Yes. That’s fine in Spanish. When the causal clause comes first, use a comma after it. When it follows the main clause, don’t put a comma before porque in standard usage:

Fronted: Porque… , ambos padres…
Postposed: Ambos padres… porque… (no comma before porque)

Is the accent in hacía and llovía important?

Yes. Hacía (he/she/it was making/doing) is different from hacia (toward). Llovía needs the accent to mark the stress and vowel break. Also frío has an accent. Omitting these tildes can change meaning or be considered a spelling error.

Where does se go in negatives or with infinitives/gerunds?

Negative finite verb: No se quedaron en casa.
With infinitive: after or attached: se iban a quedar / iban a quedarse.
With gerund: separate or attached: se estaban quedando / estaban quedándose.
With affirmative commands: attached: Quédense en casa.
With negative commands: before: No se queden en casa.

Could I use a different verb instead of quedarse?

Yes, synonyms include permanecer or seguir en (slightly different tones):

Permanecieron en casa (more formal).
Siguieron en casa (they continued to be at home). But for everyday “stay (at home),” quedarse is the most natural.