S obzirom na grešku, potrošač će osporiti zaduženje.

Yes. S obzirom na is a fixed expression meaning considering, in view of, given, or sometimes because of, depending on context.

It is best learned as one chunk. Word by word, it is related to obzir, which means consideration or regard, but learners usually do not translate it literally.

Examples:

• S obzirom na vreme... = considering the weather...
• S obzirom na okolnosti... = given the circumstances...

Because s obzirom na is followed by the accusative case, and greška is a feminine noun.

So:

• nominative: greška
• accusative: grešku

This is a very common pattern with feminine nouns ending in -a:

• poruka → poruku
• situacija → situaciju
• greška → grešku

So s obzirom na grešku is correct because the phrase requires the accusative.

This is the future I tense in Serbian.

It is formed with:

• a short form of hteti = ću, ćeš, će, ćemo, ćete, će
• plus the infinitive

Here:

• će = will for he/she/it
• osporiti = infinitive, to dispute / to challenge

So:

• potrošač će osporiti = the consumer will dispute

A few more examples:

• Ja ću platiti. = I will pay.
• Oni će doći. = They will come.

In everyday Serbian, you may also hear će da + present tense, for example će da ospori, but the version with the infinitive, će osporiti, is fully standard and very common.

Because će is a clitic in Serbian, and clitics usually go in the second position of the clause.

So:

• Potrošač će osporiti zaduženje. is natural.
• Će potrošač osporiti zaduženje is not the normal neutral order.

This second-position rule is very important in Serbian.

Compare:

• Ja ću doći.
• Marija će doći.
• Potrošač će osporiti zaduženje.

If there is no separate subject stated, Serbian can attach the future ending directly to the verb:

• Osporiće zaduženje. = He/she will dispute the charge.

This is mainly about verbal aspect.

• osporiti = perfective
• osporavati = imperfective

In this sentence, osporiti is used because it presents the action as a single completed act: the consumer will formally dispute the charge.

So:

• će osporiti = will dispute / will challenge
• će osporavati = will be disputing / will keep disputing / will dispute repeatedly, depending on context

In legal, banking, and administrative language, osporiti is very natural when someone formally contests something.

In this sentence, zaduženje most likely means a charge, debit, or amount posted to an account.

This word can have different meanings depending on context, such as:

• a financial charge or debit
• an obligation or assigned duty
• indebtedness

But in a consumer/billing context, osporiti zaduženje usually means to dispute a charge or to contest a debit.

So even if the dictionary gives several meanings, the surrounding context tells you which one is intended.

Yes, potrošač is grammatically masculine.

Its feminine form is potrošačica.

However, in formal, legal, or general statements, Serbian often uses the masculine form as a generic term, so potrošač can refer to a consumer in general, not necessarily a male person.

So in many official texts:

• potrošač = consumer, in a general category
• potrošačica = specifically a female consumer

Because S obzirom na grešku is an introductory phrase placed before the main clause, and in this kind of formal sentence it is very natural to separate it with a comma.

So the structure is:

• introductory phrase: S obzirom na grešku
• main clause: potrošač će osporiti zaduženje

In practice, with s obzirom na..., using a comma at the beginning of the sentence is a safe and natural choice, especially in formal writing.

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

• S obzirom na grešku = considering the mistake, in view of the mistake
• Zbog greške = because of the mistake

So:

• s obzirom na sounds a bit more formal and evaluative
• zbog sounds more directly causal

Both can work, but they are not always identical in tone.

The most important letters here are:

• š = sh as in shoe
• č = a harder ch as in church
• ć = a softer ch sound, with no exact English equivalent
• ž = like the s in measure
• nj = like ny in canyon

A rough pronunciation guide:

S obzirom na grešku, potrošač će osporiti zaduženje.

Approximate English-style pronunciation: s ob-ZEE-rom na GRESH-koo, po-TRO-shach ch(eh) os-po-RI-ti za-doo-ZHE-nye

A few key words:

• grešku ≈ GRESH-koo
• potrošač ≈ po-TRO-shach
• će ≈ a soft cheh
• zaduženje ≈ za-doo-ZHE-nye

The exact sound of ć in će is softer than normal English ch, so it takes a little practice.