Learn Hardcore Spanish (Latin America): Mi hijo estudia dos horas en promedio antes del examen. - My son studies for two hours on average before the exam.

Spanish simple present often expresses habitual actions. Mi hijo estudia = “My son studies (regularly),” which fits “on average.” Está estudiando is for an action happening right now.

Do I need "por" or "durante" before "dos horas"?

Not necessarily. The most natural option is the bare duration: estudia dos horas. Durante dos horas is also correct and a bit more formal/emphatic. Por dos horas is common in Latin America and acceptable, though for routines many speakers still prefer the bare duration or durante.

What does "en promedio" mean, and is it the best choice in Latin America?

It means “on average,” and it’s the standard phrase in Latin America. Good alternatives:

un promedio de: Mi hijo estudia un promedio de dos horas.
(Spain) de media, por término medio. Avoid “en media,” which is not idiomatic.

Where can I put "en promedio" in the sentence?

It’s flexible:

Mi hijo estudia en promedio dos horas antes del examen.
Mi hijo estudia dos horas en promedio antes del examen.
En promedio, mi hijo estudia dos horas antes del examen. Use commas if it’s parenthetical; otherwise, no comma is fine.

Why is it "antes del examen" and not just "antes el examen"?

Because antes takes de before a noun: antes de. When de + el combine, they contract to del: antes del examen. “Antes el examen” is ungrammatical.

When do I use "antes de" vs "antes de que"?

Before a noun/pronoun: antes de + article + noun → antes del examen.
Before an infinitive: antes de + infinitive → antes de estudiar.
Before a conjugated verb (a clause): antes de que + subjunctive → antes de que empiece el examen.

Why doesn’t "examen" have an accent, but "exámenes" does?

Singular examen ends in -n, so default stress is on the next-to-last syllable (e-XA-men); no accent needed. The plural would default to exa-ME-nes, so to keep the stress on the same syllable (XA), Spanish writes exámenes.

Could I say "Mi hija" instead of "Mi hijo"?

Yes. Hijo = son/child (masculine). For a daughter, use mi hija. For more than one child, mis hijos = my children (mixed or all boys), and mis hijas = only daughters.

What’s the difference between "mi" and "mío/mía"?

mi/mis: unstressed possessive adjectives before the noun (no accent) → mi hijo, mis hijos.
mío/mía/míos/mías: stressed possessives used after the noun or alone for emphasis/contrast → un hijo mío; el mío.

How is "estudiar" conjugated in the present?

Present indicative:

yo estudio
tú estudias
él/ella/usted estudia
nosotros/as estudiamos
ustedes/ellos/ellas estudian

Why no article with "dos horas"? Why not "las dos horas"?

With exact quantities, Spanish typically omits the article: dos horas. Las dos horas would refer to a specific, previously identified block (“the two hours we talked about”).

How do I say "about/around two hours"?

Common options in Latin America: como dos horas, unas dos horas, alrededor de dos horas, aproximadamente dos horas.

What’s the difference between "antes del examen" and "para el examen"?

antes del examen: time reference (before the exam).
para el examen: purpose or deadline (for the exam), e.g., Estudia mucho para el examen (to prepare for it).

Is "antes" the same as "delante de"?

No. Antes (de) is temporal (“before” in time). Delante de is spatial (“in front of” in place). So: antes del examen (before the exam), not “delante del examen.”

Can I say "por promedio" or "en el promedio"?

No. The idiomatic phrase is en promedio (no article). If you want the noun, use un promedio de: un promedio de dos horas.

Is "previo al examen" a good alternative to "antes del examen"?

Yes, but it’s more formal. Previo a + noun uses a (and contracts: a + el → al): Mi hijo estudia dos horas, en promedio, previo al examen.

Can "en promedio" be set off with commas?

Yes, when used parenthetically: Mi hijo estudia dos horas, en promedio, antes del examen. Without commas is also fine; the meaning doesn’t change.