Learn Hardcore Spanish (Latin America): Para la boda, mi prima compra un vestido rojo muy elegante. - For the wedding, my cousin buys a very elegant red dress.

para la boda = for the wedding / for the purpose of the wedding (goal, purpose).
She is buying the dress with the wedding in mind.
por la boda would usually mean because of the wedding or on account of the wedding, and sounds more like a general cause than a clear purpose for the action.
a la boda = to the wedding (direction, destination), as in Voy a la boda (I’m going to the wedding), not for the wedding.

So to express purpose (why she is buying the dress), para is the natural choice.

Why do we say la boda and not just para boda?

In Spanish, singular countable nouns almost always need an article (el, la, un, una) unless there is a special reason to omit it.

la boda = the wedding (a specific, known event).
boda without an article would sound incomplete here and is generally wrong in this context.

You can see the same pattern in:

Para la fiesta, compro bebidas. – For the party, I buy drinks.
Para el examen, estudio mucho. – For the exam, I study a lot.

So para la boda is the natural, grammatically complete form.

Why is it mi prima and not mi primo? How does that work?

Spanish makes a gender distinction with many family words:

primo = male cousin
prima = female cousin

So:

mi primo – my male cousin
mi prima – my female cousin

The sentence is talking about a female cousin, so mi prima is used.

Why is compra in the present tense if the wedding is in the future?

Spanish present tense often covers:

Present actions
- Mi prima compra un vestido. – My cousin is buying a dress (now).
Near future (especially when context makes it clear)
- Mañana mi prima compra un vestido. – Tomorrow my cousin will buy a dress.

In this sentence, context (para la boda) can suggest preparation for a future event, but Spanish is still comfortable using the simple present for planned or scheduled future actions, especially in spoken language.

If you want to make the future idea more explicit, you could say:

Mi prima va a comprar un vestido rojo muy elegante. – My cousin is going to buy a very elegant red dress.
Mi prima comprará un vestido rojo muy elegante. – My cousin will buy a very elegant red dress.

But compra is perfectly normal and common.

What is the difference between compra, está comprando, and va a comprar here?

All three are possible, but with slightly different focuses:

compra un vestido
Can mean:
- She buys a dress (habitual or present simple), or
- She is buying / will buy a dress (depending on context).
está comprando un vestido
Focuses on an action happening right now:
- She is buying a dress (at this moment).
va a comprar un vestido
Focuses on the near future plan or intention:
- She is going to buy a dress.

In everyday Latin American Spanish, you’ll hear all three forms, chosen according to whether the speaker wants to emphasize now, habit, or planned future.

Why is it un vestido and not el vestido?

The choice between un and el is like a vs the in English:

un vestido = a dress (not specified, just some suitable dress)
el vestido = the dress (a specific one that both speaker and listener know about)

In this sentence, we’re just saying she is buying a (some) very elegant red dress, with no prior reference:

Mi prima compra un vestido rojo muy elegante.

If they had already talked about a particular dress, they could say:

Mi prima compra el vestido rojo muy elegante.
My cousin is buying the very elegant red dress (the one we already know about).

Why is the adjective order un vestido rojo muy elegante and not un muy elegante vestido rojo?

Typical, neutral order for multiple adjectives in Spanish is:

[noun] + [most basic, inherent characteristic] + [more subjective / descriptive adjectives]

Here:

vestido = noun
rojo = basic physical characteristic (color)
muy elegante = more subjective / evaluative opinion

So natural order is:

un vestido rojo muy elegante – a very elegant red dress

un muy elegante vestido rojo is grammatically possible but:

Sounds literary, poetic, or overly stylized.
Not typical in everyday speech.

In normal conversation, un vestido rojo muy elegante is what you want.

Why is it rojo and not roja?

Adjectives in Spanish must agree in gender and number with the noun they modify.

vestido is masculine singular.
So its adjectives must also be masculine singular.

Therefore:

un vestido rojo muy elegante
- rojo (masc. sing.)
- elegante (same form for masc./fem., but still singular)

If the noun were feminine, for example falda (skirt), it would change:

una falda roja muy elegante
- falda (fem.) → roja (fem.)

Why is there no a before un vestido? In other sentences I see a before objects.

The personal a (the a before a direct object) is used mainly with:

Specific people
Sometimes pets and personified beings

Example:

Veo a mi prima. – I see my cousin.
Llamo a mi mamá. – I call my mom.

But with inanimate, non-personal direct objects, there is no personal a:

Compro un vestido. – I buy a dress.
Leo un libro. – I read a book.

Since un vestido is a thing, you do not add a before it.

Is the comma after Para la boda necessary?

The comma is:

Optional but recommended.

Para la boda is a short introductory phrase. In Spanish, short openings like this may be written:

With comma: Para la boda, mi prima compra un vestido…
Without comma: Para la boda mi prima compra un vestido…

Both are acceptable. The comma:

Makes the structure clearer.
Matches fairly well with English style: For the wedding, my cousin buys…

Could we say Para su boda instead of Para la boda? What changes?

Yes, both are correct but slightly different in focus:

Para la boda, mi prima compra un vestido…
- The wedding is understood from context; it might be her wedding or just the wedding everyone knows about.
Para su boda, mi prima compra un vestido…
- Explicitly says it is her own wedding (or possibly someone else’s, depending on context, but usually understood as hers).

If you want to be super clear that it’s her wedding, para su boda is more explicit:

Para su boda, mi prima compra un vestido rojo muy elegante.
For her wedding, my cousin is buying a very elegant red dress.

Could I say Para la boda, mi prima está comprando un vestido rojo muy elegante?

Yes, that sentence is grammatically correct.

However, note the nuance:

está comprando emphasizes an action in progress right now:
- Right now, for the wedding, my cousin is (in the process of) buying a very elegant red dress.

If you are speaking more generally about her plans or decision, without stressing “right now,” the simple present compra is more common and more neutral:

Mi prima compra un vestido rojo muy elegante.

Is there anything I should know about how this is pronounced in Latin America?

A few general points (varies by country, but these are common patterns):

boda:
- b like in baby.
- The d between vowels can sound softer, almost like a very soft th in many accents, especially in casual speech: [bo-ða] or [bó-ða].
vestido:
- v is usually pronounced like a soft b in Spanish, so it sounds closer to bestido than to English vestido.
- Again, d between vowels is often softened.
prima:
- The r is a single tap of the tongue, like the very quick tt in American English butter (in some accents).
rojo:
- r at the beginning of a word is a strong rolled r.
- j is a strong h-like sound from the throat: ro-ho.

None of these pronunciation details change the grammar, but they help you sound more natural in Latin American Spanish.