Probni rok traje tri mjeseca.

In this sentence, probni rok is the standard expression for a trial period or probation period.

• probni = trial, test, probationary
• rok = period, term, deadline, time limit

Together, probni rok is a fixed expression often used for employment, contracts, services, or other situations where something is being tested for a limited time.

Croatian does not have articles like English a and the.

So Probni rok traje tri mjeseca can mean:

• The probation period lasts three months
• A probation period lasts three months

Which one is meant depends on context.

Because probni is an adjective agreeing with rok.

Rok is:

• masculine
• singular
• nominative here

So the adjective also takes the masculine singular nominative form:

• probni rok

If the noun changed, the adjective would change too.

Traje is the 3rd person singular present tense of trajati, which means to last.

It is 3rd person singular because the subject, probni rok, is singular.

So:

• trajati = to last
• traje = lasts / is lasting

In this sentence, English usually translates it simply as lasts.

With trajati, Croatian usually gives the duration directly, without a separate word meaning for.

So Croatian says:

• traje tri mjeseca

literally something like:

• lasts three months

This is normal and natural in Croatian.

This is a very common number pattern in Croatian.

After 2, 3, and 4, nouns like mjesec usually take the form mjeseca.

So you get:

• jedan mjesec = one month
• dva mjeseca = two months
• tri mjeseca = three months
• četiri mjeseca = four months
• pet mjeseci = five months

So tri mjeseca is exactly what you expect after tri.

Rok is in the nominative singular because it is the subject of the sentence.

The basic structure is:

• Probni rok = subject
• traje = verb
• tri mjeseca = duration expression

So the thing that lasts is probni rok.

The given order, Probni rok traje tri mjeseca, is the most neutral and natural.

Croatian word order is fairly flexible, so other orders are possible, but they usually add emphasis or sound less neutral.

For example:

• Probni rok traje tri mjeseca = neutral
• Tri mjeseca traje probni rok = marked, emphasizing the length

For a learner, the original order is the best one to use.

A rough guide is:

• mjeseca ≈ mye-SE-tsa

And the whole sentence is roughly:

• PROB-nee rok TRA-ye tree MYE-se-tsa

A few useful points:

• j is pronounced like English y
• c is pronounced like ts
• traje sounds like TRA-ye
• stress is not usually marked in normal writing, so learners often focus first on clear sounds rather than perfect stress

No. It is very common for employment probation, but it can also be used more broadly for a trial period in other contexts.

Still, in many everyday situations, especially HR or work-related ones, English probation period is often the best translation. The exact English wording depends on context.