En la carnicería compramos un filete para mí y unas salchichas para mi hermano.

En la carnicería means in/at the butcher’s shop and tells you where the action happened.

• En = in / at
• A usually shows movement toward a place

So:

• En la carnicería compramos... = We bought ... at the butcher’s
• Fuimos a la carnicería = We went to the butcher’s

If you used a la carnicería with compramos, it would sound like you were focusing on movement rather than location.

Compramos is the preterite form of comprar for nosotros and is used for a completed action in the past.

• compramos = we bought
• comprábamos = we were buying / we used to buy
• hemos comprado = we have bought

In a simple sentence about one finished shopping action, compramos is the most natural choice.

In Spanish, compramos can mean either:

• we buy (present)
• we bought (preterite)

The context tells you which one is meant. Here, since the sentence is clearly narrating a completed event, it means we bought.

This is a common pattern with -ar verbs in the nosotros form:

• hablamos = we speak / we spoke
• estudiamos = we study / we studied
• compramos = we buy / we bought

This is about number and gender.

• un filete = one steak
• unas salchichas = some sausages

Also:

• filete is masculine singular, so it takes un
• salchichas is feminine plural, so it takes unas

So the articles agree with the nouns:

• un
  • masculine singular noun
• unas
  • feminine plural noun

Because mí and mi are different words.

• mí with an accent means me after a preposition
• mi without an accent means my

So:

• para mí = for me
• para mi hermano = for my brother

This is a very common distinction:

• a mí = to me
• de mí = of me / from me
• mi casa = my house
• mi hermano = my brother

Yes, when mí means me after a preposition, it always has the accent.

Examples:

• para mí = for me
• a mí = to me
• sin mí = without me

But mi without an accent means my:

• mi libro = my book
• mi madre = my mother

The accent helps distinguish the two meanings.

Because after a preposition like para, Spanish uses a prepositional pronoun, not a subject pronoun.

So:

• yo = I
• mí = me (used after prepositions)

That is why you say:

• para mí = for me
• not para yo

Other examples:

• para ti = for you
• sin él = without him
• con ella = with her

Para here means for in the sense of intended for or meant for someone.

• un filete para mí = a steak for me
• unas salchichas para mi hermano = some sausages for my brother

This shows who each item was intended for.

This is a very typical use of para:

• un regalo para Ana = a gift for Ana
• comida para los niños = food for the children

Not in this sentence.

Para is correct because it expresses destination/purpose/recipient: who the food is for.

• para mí = for me
• para mi hermano = for my brother

Por usually has other meanings, such as:

• because of
• through
• by
• for the sake of
• in exchange for

So compramos un filete por mí would not mean the same thing. It could suggest something like because of me or on my behalf, which is not the idea here.

Because mi hermano is not the direct object of the verb compramos.

We bought:

• un filete
• unas salchichas

Those are the things bought.
para mi hermano is just a phrase telling you for whom the sausages were intended.

The personal a is used before a person who is a direct object, for example:

• Veo a mi hermano = I see my brother
• Llamamos a Ana = We called Ana

But here, mi hermano is not the direct object, so no personal a is needed.

This is a very natural Spanish word order:

1. verb: compramos
2. thing bought: un filete
3. recipient: para mí
4. second thing bought: unas salchichas
5. second recipient: para mi hermano

Spanish is fairly flexible with word order, but this version is clear and natural because each item is followed by who it was for.

You could also hear variations depending on emphasis, but this sentence is straightforward and standard.

Yes, in some contexts it could.

If it is already clear that the speaker is talking about their own steak, someone might simply say:

• En la carnicería compramos un filete y unas salchichas para mi hermano.

That would usually imply the steak was for the speaker or for the group, depending on context.

But including para mí makes the contrast very clear:

• the steak was for me
• the sausages were for my brother

Because carnicería is a feminine noun, so it takes la:

• la carnicería

Many nouns ending in -ía are feminine:

• la panadería
• la frutería
• la cafetería

As always, the article must agree with the noun’s gender.

In Spain, filete usually means a slice/cut of meat, often translated as steak or fillet depending on context.

At a butcher’s shop, un filete would normally be understood as a cut of meat, often beef or pork depending on context. In everyday learning, steak is a good translation.

Yes. In this sentence, unas salchichas is best understood as some sausages.

The indefinite plural articles unos/unas often mean:

• some
• a few

The exact number is not important. It just means more than one, but unspecified.

So:

• unas salchichas = some sausages

Yes, it is natural and correct in Spain Spanish.

Everything in it is standard:

• En la carnicería for location
• compramos for a completed past action
• para mí / para mi hermano for intended recipients
• normal article and noun agreement

A native speaker in Spain would understand it immediately and would find it perfectly natural.