Zanima me ovaj posao.

That is exactly how Serbian usually expresses this idea.

• zanimati = to interest
• ovaj posao = this job
• me = me

So the structure is literally:

• Ovaj posao me zanima = This job interests me

In natural English, that often becomes I’m interested in this job, but Serbian commonly uses the interest someone pattern instead of the English adjective pattern.

Because the verb agrees with ovaj posao, not with me.

In this sentence, the thing doing the interesting is ovaj posao. That noun phrase is:

• masculine
• singular
• nominative

So the verb is in 3rd person singular:

• ja zanimam = I interest
• on/ona/ono zanima = he/she/it interests

Here, ovaj posao is grammatically the subject, so you need zanima.

Because me is the unstressed object form of I.

Compare:

• ja = I → subject form
• me = me → short clitic object form
• mene = me → full/stressed object form

In Zanima me ovaj posao, the person being affected is the object, so ja would be wrong.

Why not mene?
Because Serbian usually prefers the short clitic form when there is no special emphasis:

• Zanima me ovaj posao. = normal, neutral
• Mene zanima ovaj posao. = emphasizes me
• Ovaj posao zanima mene. = possible, but strongly marked/emphatic

It is in the nominative singular.

Why?

Because ovaj posao is the grammatical subject of the sentence, even though it comes after the verb.

Both words are masculine singular nominative:

• ovaj = this (masculine singular nominative)
• posao = job/work (masculine singular nominative)

So the sentence is built like:

• [subject] ovaj posao
• [verb] zanima
• [object] me

Even if the word order changes, the case stays the same.

Yes, absolutely.

Both are correct:

• Zanima me ovaj posao.
• Ovaj posao me zanima.

The difference is mostly about focus and word order.

• Ovaj posao me zanima. often sounds a bit more neutral or straightforward.
• Zanima me ovaj posao. can put a little more focus on this job as the thing of interest.

One important rule: the clitic me usually cannot stand alone at the very beginning of the sentence. It tends to appear in second position, so forms like Me zanima ovaj posao are not standard.

Posao most commonly means:

• job
• work
• sometimes task or business

In ovaj posao, the most natural translation is usually this job.

Depending on context, it could also mean:

• this line of work
• this work
• this position

So if someone is talking about employment, Zanima me ovaj posao usually means I’m interested in this job/position.

There are other ways, but zanima me is one of the most natural and common.

Some alternatives:

• Interesuje me ovaj posao.
  Also means This job interests me / I’m interested in this job.
  Very close in meaning.

• Zainteresovan sam za ovaj posao.
  Literally I am interested in this job.
  This uses an adjective-like form zainteresovan and the preposition za.

The nuance is roughly:

• zanima me = this job interests me; very everyday and natural
• interesuje me = similar, sometimes a bit more formal or bookish depending on speaker
• zainteresovan sam za = I am interested in; often useful in formal or professional contexts

You simply add ne before the verb:

• Ne zanima me ovaj posao. = This job doesn’t interest me / I’m not interested in this job.

That is the normal Serbian way to negate it.

A few common ways are:

• Da li te zanima ovaj posao? = Are you interested in this job?
• Zanima li te ovaj posao? = same meaning
• Je l’ te zanima ovaj posao? = very common in speech

If you want to ask about yourself, you usually would not ask Zanima me ovaj posao? by itself. Instead, that sentence is naturally a statement: I’m interested in this job.

A simple learner-friendly pronunciation guide is:

• Za-ni-ma me o-vaj po-sao

Approximate English-style help:

• ZA-nee-ma meh OH-vai PO-sa-o

A few notes:

• j in Serbian sounds like English y
• ovaj sounds roughly like OH-vai
• posao has three syllables: po-sa-o

If you pronounce each vowel clearly, you will already sound much better:

• a, e, i, o, u are usually pure and consistent in Serbian

Yes. Me is a clitic, which means it is a short unstressed word with special placement rules.

In Serbian, clitics usually go near the beginning of the sentence, often in second position. That is why these sound natural:

• Ovaj posao me zanima.
• Zanima me ovaj posao.

But me normally does not carry stress and does not like standing independently.

This is an important pattern to get used to, because the same thing happens with other short forms too:

• te
• ga
• je
• nas
• vam
• ih

So learning me here also helps with a much bigger Serbian grammar pattern.