Radni odnos na određeno vreme ima otkazni rok.

Not exactly. Radni odnos is a more formal/legal expression meaning employment relationship or employment status. It refers to the legal relationship between an employee and an employer.

In everyday English, it may be translated more naturally as employment, but it is more formal than simply job.

For example:

• radni odnos = employment relationship / employment
• posao = job / work

So this sentence sounds more legal or administrative than casual.

This is a fixed Serbian expression meaning for a fixed period or for a definite period of time.

Grammatically:

• na here is followed by the accusative
• vreme is a neuter singular noun
• određeno agrees with vreme, so it is also neuter singular

That is why you get:

• na određeno vreme

Compare:

• ugovor na određeno vreme = a fixed-term contract
• radni odnos na određeno vreme = fixed-term employment

Because it agrees with vreme, which is a neuter noun.

In Serbian, adjectives must agree with the noun in:

• gender
• number
• case

Since vreme is:

• neuter
• singular
• here in the accusative form

the adjective must match it:

• određeno

So:

• masculine: određeni
• feminine: određena
• neuter: određeno

It is in the accusative singular, because it follows the preposition na in this expression.

However, with neuter singular nouns like vreme, the nominative and accusative forms are the same, so you do not see a visible ending change.

So:

• nominative: vreme
• accusative: vreme

That is why the form looks unchanged.

It is the direct object of ima, so it is in the accusative.

But there is an important detail: otkazni rok is masculine and inanimate, and for masculine inanimate nouns, the accusative singular is the same as the nominative singular.

So:

• nominative: otkazni rok
• accusative: otkazni rok

That is why it looks like a subject form, even though it is actually the object.

Because Serbian often uses imati = to have in this kind of statement.

Literally, the sentence says:

• A fixed-term employment relationship has a notice period.

That is a normal Serbian way of expressing the idea.

English might sometimes prefer something like:

• There is a notice period for fixed-term employment or
• Fixed-term employment includes a notice period

But in Serbian, ima is perfectly natural.

You can tell from the sentence structure and the verb:

• Radni odnos na određeno vreme is in the nominative
• ima is 3rd person singular
• the whole phrase acts as the thing that has something

So the structure is:

• Subject: Radni odnos na određeno vreme
• Verb: ima
• Object: otkazni rok

In English order:

• Fixed-term employment / employment for a fixed period = subject
• has = verb
• a notice period = object

Because Serbian has no articles.

English says:

• a notice period
• the notice period

Serbian simply says:

• otkazni rok

Whether it means a or the depends on context.

This is very common for English speakers to notice, because Serbian does not mark definiteness with articles the way English does.

Otkazni rok means notice period, especially in an employment context.

It is made of:

• otkazni = relating to notice/termination/dismissal
• rok = period, deadline, term

So together:

• otkazni rok = notice period

In work-related language, this usually refers to the period between giving notice and the actual end of employment.

Yes. Serbian word order is fairly flexible, although the original sentence is neutral and natural.

For example, you could also say:

• Otkazni rok ima radni odnos na određeno vreme.

But that sounds marked or stylistically unusual in most contexts.

The original:

• Radni odnos na određeno vreme ima otkazni rok.

is the most straightforward way to present the information.

They are closely related, but not always exactly the same.

• ugovor na određeno vreme = fixed-term contract
• radni odnos na određeno vreme = fixed-term employment / employment relationship for a fixed period

In many practical situations, they refer to almost the same real-world situation, but:

• ugovor focuses on the contract
• radni odnos focuses on the employment relationship

So in legal or administrative language, the distinction can matter.

Literally, yes, but in actual usage it means a fixed period or a definite period.

This is one of those phrases where a word-for-word translation sounds less natural in English than the real meaning.

So:

• na određeno vreme = for a fixed term / for a definite period
• opposite: na neodređeno vreme = for an indefinite period / permanent

That contrast is extremely common in employment language.

The usual opposite is:

• radni odnos na neodređeno vreme

This means permanent employment or employment for an indefinite period.

So the key contrast is:

• na određeno vreme = fixed-term
• na neodređeno vreme = indefinite / permanent

This pair is very important in Serbian labor and contract vocabulary.