La fleca on compra pa la meva germana és a prop de casa.

On means where.

In La fleca on compra pa la meva germana..., the word on introduces a relative clause that describes la fleca:

• la fleca = the bakery
• on compra pa la meva germana = where my sister buys bread

So on is the place-word linking the bakery to the action that happens there.

A more formal alternative is possible, such as a la qual, but on is the normal, natural choice in everyday Catalan.

Catalan word order is more flexible than English word order.

In English, you would normally say:

• where my sister buys bread

But in Catalan, both of these are possible:

• on compra pa la meva germana
• on la meva germana compra pa

The version with the subject after the verb is very natural in Catalan, especially in relative clauses like this one. It does not sound strange to a native speaker.

So:

• compra = buys
• la meva germana = my sister

Even though English strongly prefers my sister buys, Catalan often allows buys my sister without sounding unusual.

Because pa here is being used in a general, non-specific sense: bread as a thing someone buys, not a particular bread.

So:

• compra pa = buys bread
• compra el pa = buys the bread / buys the household bread / buys bread in a more specific sense

This is similar to English, where we often say buy bread, not buy the bread, unless we mean a specific loaf or a specific bread already known from context.

So compra pa is perfectly natural when the idea is simply she buys bread there.

Catalan usually uses the definite article with possessives:

• la meva germana = my sister
• el meu germà = my brother
• la meva mare = my mother

This is one of the most noticeable differences from English. In English, my already feels enough by itself, but in Catalan the article is normally still there.

So the pattern is usually:

• article + possessive + noun

Examples:

• la meva casa = my house
• el teu cotxe = your car
• els nostres amics = our friends

There are some exceptions in certain set expressions or styles, but for a learner, use the article as the default rule.

A prop de means near or close to.

So:

• a prop de casa = near home

This is a fixed expression:

• a prop de l’escola = near the school
• a prop del riu = near the river
• a prop de casa = near home

The important thing is that a prop works together with de. So you should learn it as a unit:

• a prop de...

not just a prop...

Because casa here means home, not the house as a specific building.

Catalan often uses casa without an article in expressions connected with the idea of home:

• ser a casa = to be at home
• anar a casa = to go home
• tornar a casa = to return home
• a prop de casa = near home

If you said de la casa, it would sound more like of the house or near the house, referring to a specific building rather than the general idea of home.

So:

• a prop de casa = near home
• a prop de la casa = near the house

The accent distinguishes és from es.

• és = is
• es = reflexive or object pronoun, often meaning himself/herself/itself/themselves or part of a pronominal verb

Examples:

• Ella és aquí. = She is here.
• Es renta les mans. = She washes her hands.

So in your sentence:

• és is the 3rd person singular of ser: is

The accent is important because it changes the word entirely.

Yes. That is also correct.

These two versions are both natural:

• La fleca on compra pa la meva germana és a prop de casa.
• La fleca on la meva germana compra pa és a prop de casa.

The difference is mainly one of word order and rhythm, not basic meaning.

For an English speaker, the second version may feel easier at first because it matches English word order more closely:

• where my sister buys bread

But the first version is very normal Catalan, so it is worth getting used to it.

Yes, you could, but the nuance changes a little.

• compra pa = buys bread, in a general sense
• compra el pa = buys the bread / buys bread for the household / buys the usual bread

In real life, comprar el pa is very common, because people often mean buy the bread in the everyday sense of getting bread for the house.

So both can work, but:

• pa sounds more general
• el pa sounds more specific or more like a routine household purchase

No. Fleca is a correct and common word, but depending on the region, you may also hear:

• forn
• forn de pa

All of these can refer to a bakery, especially a bread bakery.

Very roughly:

• fleca = bakery
• forn = oven / bakery
• forn de pa = bread bakery

Regional preference varies, so if you hear another word in Catalan for bakery, that does not mean fleca was wrong.

Both verbs are in the present indicative:

• compra = buys
• és = is

The present tense is used here for two normal reasons:

1. Habitual action
   compra pa means that this is where your sister buys bread, as a usual or regular action.

2. Current fact
   és a prop de casa states a present fact: the bakery is near home.

This is very similar to English, which also uses the present tense in this type of sentence:

• The bakery where my sister buys bread is near home.

Not in this sentence.

After a place noun like la fleca, the normal relative word is simply on:

• La fleca on compra pa...

Using a on here would not be the standard choice.

Learners sometimes think of English to where or at which, but Catalan usually just uses on in this kind of relative clause.

In questions, depending on region and style, you may hear both:

• On vas? = Where are you going?
• A on vas? = Where are you going?

But in your sentence, on is the right form.