Learn Hardcore Spanish (Latin America): Mi hermana revisa su agenda cada noche antes de dormir. - My sister checks her planner every night before sleeping.

It’s the present indicative, third-person singular of revisar (to check/review). It means “she checks.” Quick paradigm: yo reviso, tú revisas, él/ella/usted revisa, nosotros revisamos, ustedes/ellos revisan. Spanish simple present often expresses habits, so it naturally covers “checks every night.”

Whose agenda is su agenda? Could it be someone else’s?

Su is ambiguous in Spanish: it can mean “his,” “her,” “your (formal),” or “their.” In this sentence, context suggests it’s her own. To remove ambiguity, say la agenda de mi hermana or su propia agenda (her own planner).

What does agenda mean in Latin American Spanish?

Usually a personal planner/diary or someone’s schedule of appointments. For a wall or digital calendar, calendario is more common. For a meeting agenda (list of items), many say orden del día or still agenda in modern usage; context clarifies.

Is there any difference between cada noche and todas las noches?

Both mean “every night.” Cada noche sounds a bit more concise/neutral; todas las noches can feel slightly more emphatic or colloquial. Both are fine.

Why is it antes de and not something like antes que or antes a?

With an infinitive, Spanish uses antes de + infinitivo: antes de dormir. When followed by a finite clause, use antes de que + subjuntivo: antes de que se duerma. Antes a is incorrect here; antes que is used in comparisons (e.g., “rather than”).

Why is it dormir and not dormirse?

Both exist but aren’t identical:

dormir = to sleep (general activity). Antes de dormir = before sleeping/going to sleep (idiomatic).
dormirse = to fall asleep (the moment you drift off). Antes de dormirse emphasizes “before falling asleep.” In everyday speech, antes de dormir is very common and natural.

Could I say antes de que se duerma instead? Do I need the subjunctive?

Yes: antes de que se duerma (“before she falls asleep”) is correct and uses the subjunctive, which is required after antes de que. Use this structure when you want a full clause or when the subject changes. With the same subject, the infinitive version antes de dormir is typically preferred for brevity.

Is the word order flexible? Can I move cada noche?

Yes. All are acceptable, with subtle emphasis shifts:

Mi hermana revisa su agenda cada noche... (neutral)
Cada noche, mi hermana revisa su agenda... (emphasizes the time frame)
Mi hermana, cada noche, revisa su agenda... (more marked/stylistic)
Mi hermana cada noche revisa su agenda... (informal but heard)

Why isn’t there a personal a before su agenda?

The personal a is used with direct objects that are people (or personified animals/objects). Agenda is an inanimate thing, so: revisa su agenda (no a).

Why does mi have no accent, but sometimes I see mí?

Mi (no accent) is the possessive adjective “my,” as in mi hermana. Mí (with accent) is the prepositional pronoun “me,” used after prepositions: para mí, a mí. In this sentence we need the possessive, so no accent.

Why is it su and not sus? Does su agree with the possessor’s gender?

Su/sus agree with the thing possessed, not the possessor. Agenda is singular, so su. If it were plural (agendas), you’d use sus. There’s no gender change for su.

Could I use another verb instead of revisar?

Yes, depending on region/register:

chequear (widely understood) or checar (very common in Mexico) = “to check”
ver (“to look at”) is casual: ver su agenda
repasar (“to go over”) if she reviews items carefully Revisar is standard and neutral.

Can I replace su agenda with a pronoun?

If the context already established “the agenda,” you can say: Mi hermana la revisa cada noche... (la because agenda is feminine singular).

Any pronunciation tips for key words?

agenda: the g before e sounds like an English h (varies from h to a harsher kh): a-HEN-dah.
revisa: the Spanish v sounds like a soft b; roughly reh-BEE-sah (Latin American).
hermana: the initial h is silent; the single r is a light tap.

How would I talk about past or future habits/actions?

Ongoing habit (present): Mi hermana revisa...
Past habit: Mi hermana revisaba su agenda... (imperfect)
Single past event: Mi hermana revisó su agenda anoche. (preterite)
Recent past (many regions): Mi hermana ha revisado su agenda. (present perfect; usage varies by region)
Future: Mi hermana revisará su agenda esta noche.