Zbog reklamacije prodavac šalje zamenu.

Because zbog requires the genitive case.

• Basic form: reklamacija
• After zbog: reklamacije

So zbog reklamacije means because of the complaint / claim.

This is a very common pattern in Serbian:

• zbog problema = because of the problem
• zbog kiše = because of the rain
• zbog reklamacije = because of the complaint

In Serbian, reklamacija usually means a customer complaint, return claim, or warranty claim about a product or service.

It does not mean advertisement.
That word is reklama.

So:

• reklama = advertisement
• reklamacija = complaint / claim about faulty goods or service

In this sentence, it refers to a complaint that leads the seller to send a replacement.

Because zamenu is the accusative singular form, and it is the direct object of šalje.

• Nominative: zamena = replacement
• Accusative: zamenu = replacement, as the thing being sent

So:

• Zamena je stigla. = The replacement arrived.
  Here zamena is the subject.
• Prodavac šalje zamenu. = The seller is sending a replacement.
  Here zamenu is the object.

Since zamena is a feminine noun ending in -a, its accusative singular changes to -u.

Šalje is 3rd person singular present tense.

It comes from the verb slati = to send.

So prodavac šalje means:

• the seller sends
• the seller is sending

Depending on context, Serbian present tense can sometimes also sound natural in English as will send, especially in practical or business situations, but grammatically it is present tense.

Also, slati is an imperfective verb. Its common perfective partner is poslati.

• šalje = is sending / sends
• pošalje = sends off / will send once, as a completed action

Because Serbian does not have articles like English the and a/an.

So prodavac can mean:

• a seller
• the seller

And zamenu can mean:

• a replacement
• the replacement

Context tells you which is meant. In a customer-service sentence like this, English would often use the seller and a replacement or the replacement, depending on the situation.

Yes. Serbian word order is much more flexible than English word order.

This sentence starts with Zbog reklamacije to foreground the reason:

• Zbog reklamacije prodavac šalje zamenu.

You could also say:

• Prodavac šalje zamenu zbog reklamacije.

Both are grammatical. The difference is mainly in focus and information flow.

• Starting with Zbog reklamacije highlights the reason first.
• Starting with Prodavac is a bit more straightforward and subject-first.

Prodavac is the masculine noun for seller / salesman, but it can also be used generically in some contexts.

If you specifically want to say female seller, Serbian often uses:

• prodavačica

So you could have:

• Prodavačica šalje zamenu. = The saleswoman/female seller is sending a replacement.

In business or general statements, masculine forms are sometimes used in a generic sense.

A rough English-friendly pronunciation is SHA-lyeh.

A few key points:

• š sounds like sh in shoe
• lj is a single Serbian sound, similar to the lli sound in million for many English speakers
• e is pronounced clearly, like e in bet, not silent

So šalje is not pronounced like sha-lee or shalj. The lj is one blended sound.

It can mean a few related things, depending on context:

• replacement
• substitute
• exchange

In this sentence, because the seller is sending something after a complaint, zamenu most naturally means a replacement item.

So here it is not an abstract exchange in general, but the actual replacement being sent to the customer.

Yes. Zbog is a very common and natural way to say because of in Serbian.

It is neutral and widely used in everyday language:

• zbog gužve = because of the traffic/crowd
• zbog bolesti = because of illness
• zbog reklamacije = because of the complaint

Just remember the grammar rule: zbog is followed by the genitive case.

Yes. In a shopping or customer-service context, šalje very often means ships, dispatches, or sends out.

So prodavac šalje zamenu can naturally refer to the seller physically sending a replacement product to the customer.

Serbian uses slati in a broad way, just like English send can mean:

• send a message
• send an email
• send a package

Here the context makes it clear that it is probably a product being shipped.