Voy a devolver el dinero a mi hermano mañana.

“Voy a devolver” is the “ir a + infinitive” construction, often called the “going to” future.

• ir (voy) = I go / I’m going
• a = to
• devolver = to return / to give back

So “voy a devolver” literally looks like “I’m going to return”, and it works very much like English “I’m going to give back…” to talk about a future plan or intention.

It’s extremely common in everyday speech in Latin America to talk about things you’re planning to do in the (usually near) future.

Yes, you can say “Devolveré el dinero a mi hermano mañana.” It’s grammatically correct.

Difference in feel:

• Voy a devolver el dinero…

  • Sounds like a concrete plan or intention, often near future.
  • Very common in spoken Latin American Spanish.

• Devolveré el dinero…

  • Uses the simple future tense.
  • Can sound a bit more formal, more distant, or more “statement-like.”
  • Still used in speech, but in everyday conversation, many people prefer “voy a + infinitive”.

In many contexts, both mean the same: “I’ll give the money back to my brother tomorrow.”

Spanish usually drops subject pronouns (yo, tú, él, etc.) when the verb ending already makes it clear who the subject is.

• voy already tells you it’s “I” (first person singular).
• So “Yo voy a devolver…” is correct but often sounds emphatic:
  
  • “Yo voy a devolver el dinero, no tú.” – I am going to give the money back, not you.

In neutral, everyday speech, “Voy a devolver el dinero…” (without yo) is more natural.

Both are possible, but they don’t mean exactly the same thing:

• Voy a devolver el dinero…

  • “el dinero” = the money
  • Refers to specific money we both know about (e.g., the money I borrowed from my brother).

• Voy a devolver dinero…

  • “dinero” without article is more general or indefinite, like “(some) money” or “money (in general).”
  • Used more when the exact money isn’t specified or doesn’t matter.

In the context “I’m going to give my brother his money back,” we’re talking about a specific sum he lent you, so “el dinero” is the natural choice.

The “a” here is the preposition that introduces the indirect object: the person receiving the returned money.

• devolver el dinero a mi hermano
  = return the money to my brother

In Spanish, you generally show the person who receives something (or who benefits from an action) with “a + person”:

• Dar un regalo a mi madre – to give a present to my mom
• Prestar el libro a Juan – to lend the book to Juan

So “a mi hermano” answers “to whom?” – to my brother.

Both a and para can appear with a person, but they aren’t interchangeable here.

• a mi hermano

  • Marks the indirect object: who receives something or is affected by the action.
  • “Voy a devolver el dinero a mi hermano.” – I’m giving the money back to him.

• para mi hermano

  • Means “for my brother” in the sense of destined for / intended for / on behalf of:
    • Este regalo es para mi hermano. – This gift is for my brother.
    • Voy a ahorrar dinero para mi hermano. – I’m going to save money for my brother.

In “devolver el dinero”, we’re talking about giving it back to its owner, so the natural preposition is a, not para.

Yes, that’s correct. In fact, native speakers do this a lot.

Two main options:

1. With an indirect object pronoun only

   • Voy a devolverle el dinero mañana.
   • Le voy a devolver el dinero mañana.
     Both mean: I’m going to give him the money back tomorrow.
   • le = to him / to her / to you (formal, singular).

2. With pronoun + explicit noun (very common in speech)

   • Le voy a devolver el dinero a mi hermano mañana.
   • Voy a devolverle el dinero a mi hermano mañana.
     Spanish often repeats the indirect object twice (pronoun + “a + person”) for clarity/emphasis. This is natural and correct.

So yes:
“Voy a devolverle el dinero mañana” is perfectly fine.

Both positions are correct with a + infinitive:

• Before the main verb (more neutral in speech):

  • Le voy a devolver el dinero mañana.

• Attached to the infinitive:

  • Voy a devolverle el dinero mañana.

Meaning doesn’t change; it’s mostly a matter of style and rhythm. Both are widely used in Latin America.

Yes, “mañana” (tomorrow) is flexible in position. All of these are natural:

• Mañana voy a devolver el dinero a mi hermano.
• Voy a devolver el dinero a mi hermano mañana.
• Voy a devolver mañana el dinero a mi hermano. (a bit less common but still correct)

Spanish often places time expressions at the beginning or the end of the sentence. Beginning can add a bit of emphasis: “Tomorrow, I’m going to give the money back…”

“mañana” can mean two different things:

1. tomorrow – as an adverb of time (that’s the meaning in this sentence)

   • Voy a devolver el dinero mañana. – I’m going to give the money back tomorrow.

2. morning – as a noun:

   • la mañana – the morning
   • por la mañana – in the morning

You usually know the meaning by context and by the words around it:

• If there is no article (la, una, etc.) and it’s about future time, it’s usually “tomorrow.”
• If you see la mañana, esta mañana, por la mañana, that’s “morning.”

Spanish doesn’t normally double the possessive the way English sometimes does.

• mi hermano = my brother
• mi propio hermano = my own brother
• mío alone (after a noun) is used like “mine”:
  • Ese hermano es mío. – That brother is mine.

So you do not say “mi hermano mío” in standard Spanish. To emphasize “my own brother,” you’d say:

• Es mi propio hermano. – He’s my own brother.

You should use devolver here.

• devolver = to give back / return (something to its owner)

  • Voy a devolver el dinero a mi hermano.
    This is the standard, natural verb here.

• volver

  • Usually intransitive: volver = to come back / go back.
  • No: “volver el dinero” is not how you say “return the money.”

• regresar

  • Often used like volver: to come back / go back.
  • In some parts of Latin America, you might hear “regresar algo” (to return something), but “devolver” is clearer and more universal when talking about giving something back.

So for “to give the money back,” stick with devolver el dinero.

In many Latin American countries, “plata” is a very common colloquial word for money.

• Voy a devolver la plata a mi hermano mañana.

This would sound natural in places like Argentina, Chile, Colombia (informally), parts of Central America, etc.

However:

• “dinero” is standard and understood everywhere.
• “plata” is more colloquial/regionally marked.

If you’re learning, using “dinero” is always safe; learning “plata” is helpful for understanding everyday speech.

Only the noun for the person changes:

• Voy a devolver el dinero a mi hermana mañana.
  = I’m going to give the money back to my sister tomorrow.

Everything else (voy a devolver, el dinero, mañana) stays the same. The preposition “a” is still used, because it still marks the person who receives the money.