Na pijaci kupujem sveže voće.

In Serbian, na is often used for places that are thought of as open public spaces, surfaces, or venues, and pijaca (market) is one of those nouns that commonly takes na.

So Serbian says:

• na pijaci = at the market

This is something you mostly learn as a fixed usage. English says at the market, and Serbian uses na here, not u.

Pijaci is in the locative singular.

The preposition na can take different cases depending on meaning:

• na + accusative = movement toward something
• na + locative = location, being at/on/in a place

Here the sentence describes where the action happens, so Serbian uses locative:

• na pijaci = at the market

Base noun:

• pijaca = market

Locative singular:

• pijaci

Because Serbian nouns change form depending on their grammatical role.

Pijaca is the dictionary form, but after na when it means location, it must go into the locative singular:

• pijaca → basic form
• na pijaci → locative form

This kind of change is very common in Serbian and is one of the core features English speakers need to get used to.

Kupujem means I buy or I am buying, depending on context.

It comes from the verb kupovati / kupiti (to buy). In this sentence, kupujem is the 1st person singular present tense form:

• ja kupujem = I buy / I am buying

Serbian present tense can often cover both the English simple present and present progressive, so context decides whether it means:

• I buy fresh fruit at the market or
• I’m buying fresh fruit at the market

Because Serbian usually does not need the subject pronoun when the verb already shows who the subject is.

The ending -em in kupujem tells you the subject is I.

So:

• Kupujem = I buy / I am buying
• Ja kupujem = I buy, with extra emphasis on I

You can include ja if you want contrast or emphasis, but normally it is omitted.

Yes. Sveže agrees with voće in gender, number, and case.

• voće is neuter singular
• so the adjective must also be neuter singular
• that gives sveže

Compare:

• svež hleb = fresh bread (masculine singular)
• sveža jabuka = fresh apple (feminine singular)
• sveže voće = fresh fruit (neuter singular)

So sveže is the correct adjective form here.

In Serbian, voće is a collective or mass noun, and it is grammatically treated as singular neuter.

So even though it can refer to many pieces of fruit, the grammar is singular:

• ovo voće = this fruit
• sveže voće = fresh fruit

This is similar to English fruit, which can also behave like a mass noun in many contexts.

Here voće is in the accusative singular, because it is the direct object of kupujem.

However, for many neuter singular nouns, the accusative looks the same as the nominative. So:

• nominative: voće
• accusative: voće

That is why the form does not visibly change.

Yes, Kupujem sveže voće na pijaci is also correct.

Serbian word order is more flexible than English because case endings show grammatical relationships. Different word orders often change focus or emphasis, not the core meaning.

• Na pijaci kupujem sveže voće.
  Emphasis is slightly on where the action happens: At the market, I buy fresh fruit.

• Kupujem sveže voće na pijaci.
  More neutral for many learners: I buy fresh fruit at the market.

So the original sentence is perfectly natural, but it may sound a bit more focused on the location.

Yes. In this sentence, na pijaci means at the market / at the marketplace.

Even though na often literally means on, you should not translate it word-for-word here. This is a normal Serbian expression for location.

So the natural English meaning is:

• at the market
• at the marketplace

not usually on the market, which means something different in English.

Yes, very common.

Sveže voće is a natural everyday phrase meaning fresh fruit. You will often see similar combinations:

• sveže povrće = fresh vegetables
• svež hleb = fresh bread
• sveža riba = fresh fish

So this is a very useful adjective-noun pattern to remember.

It can be either one, depending on context.

Kupujem in the present tense can mean:

• a habit / regular action
  I buy fresh fruit at the market.

• an action happening right now
  I’m buying fresh fruit at the market.

Without more context, Serbian allows both readings.

You could say:

• Na pijaci kupujem sveže voće svake nedelje.

or more neutrally:

• Kupujem sveže voće na pijaci svake nedelje.

Here svake nedelje means every week. Adding a time expression makes the habitual meaning clearer.