Ugovor na određeno vrijeme ili ugovor na neodređeno vrijeme?

Yes, Croatian could shorten it to Ugovor na određeno ili na neodređeno vrijeme? and native speakers would understand it.

In your sentence, ugovor is repeated for clarity and balance:

• ugovor na određeno vrijeme
• ili
• ugovor na neodređeno vrijeme

This is very natural in formal language, job ads, HR contexts, and legal or administrative wording. Repeating the noun makes the contrast especially clear.

Ugovor means contract or agreement.

Grammatically:

• it is a masculine noun
• it is singular
• here it is in the nominative case

In this sentence, it is the main noun in both halves of the question.

Literally, na određeno vrijeme means something like for a determined time or for a specified period of time.

In natural English, this usually corresponds to:

• fixed-term
• temporary
• for a set period

So ugovor na određeno vrijeme is a fixed-term contract.

Literally, na neodređeno vrijeme means for an undetermined time or for an unspecified period.

In natural English, this is usually:

• indefinite-term
• permanent
• open-ended

So ugovor na neodređeno vrijeme is an indefinite contract or permanent contract, depending on context.

Because they agree with vrijeme, which is a neuter singular noun.

Here is the agreement:

• određen = masculine
• određena = feminine
• određeno = neuter

And since vrijeme is neuter singular, Croatian uses:

• određeno vrijeme
• neodređeno vrijeme

So the adjective form is chosen to match vrijeme, not ugovor.

Yes, vrijeme usually means time, and it can also mean weather depending on context.

In this sentence, it clearly means time period or duration. So:

• određeno vrijeme = a fixed period
• neodređeno vrijeme = an indefinite period

This is a very common use of vrijeme in Croatian.

In this expression, na is part of the standard way Croatian says that something lasts for a certain period.

So:

• na određeno vrijeme
• na neodređeno vrijeme

This is just the normal idiomatic pattern. You should learn these as fixed expressions.

Also, after na, the noun phrase here is in the accusative case:

• na određeno vrijeme
• na neodređeno vrijeme

Since vrijeme is a neuter noun, its nominative and accusative singular forms look the same, so you do not see a visible ending change.

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

However, vrijeme looks the same in both:

• nominative singular: vrijeme
• accusative singular: vrijeme

So even though the case is accusative here, the form does not change visibly.

Ili means or.

It connects the two alternatives:

• ugovor na određeno vrijeme
• ugovor na neodređeno vrijeme

Its position is straightforward: it goes between the two choices, just like or in English.

Because this is an elliptical question. Croatian, like English, often leaves out words that are easy to understand from context.

So instead of saying something like:

• Želite li ugovor na određeno vrijeme ili ugovor na neodređeno vrijeme?
• Je li to ugovor na određeno vrijeme ili ugovor na neodređeno vrijeme?

the language simply gives the two options:

• Ugovor na određeno vrijeme ili ugovor na neodređeno vrijeme?

English does the same:

• Tea or coffee?
• Permanent or temporary contract?

Yes, very often.

In everyday speech, people often say simply:

• raditi na određeno
• biti na određeno
• raditi na neodređeno
• biti na neodređeno

For example:

• On radi na određeno.
• Dobila je posao na neodređeno.

So the full forms with ugovor and vrijeme are common in formal or precise wording, but shorter versions are extremely common in conversation.

The tricky part for English speakers is đ.

A rough guide:

• đ sounds somewhat like the j in judge, but softer
• određeno is approximately od-REH-je-no
• neodređeno is approximately neh-od-REH-je-no

This is only approximate, but the key point is:

• dž in Croatian is a stronger sound, like English j
• đ is softer

Also note:

• č and ć are different sounds
• đ is different from both d and dž

In standard Croatian, the correct form is vrijeme.

You may see or hear vreme in:

• Serbian
• some regional speech
• informal cross-border contexts

But if you are learning standard Croatian, use:

• ugovor na određeno vrijeme
• ugovor na neodređeno vrijeme

It sounds neutral to formal.

It is especially typical in:

• job advertisements
• HR documents
• legal or administrative texts
• workplace discussions

It is not unnatural in speech, but in casual conversation people often shorten it, for example:

• Na određeno ili na neodređeno?
• Je li ugovor na određeno?

So the full sentence is perfectly natural, but it has a slightly more official feel.