Rok je sutra.

Here rok means deadline, due date, or time limit.

Depending on context, rok can also mean term or period, but in a sentence like Rok je sutra, the natural interpretation is The deadline is tomorrow.

Serbian does not have articles like the or a/an.

So rok can mean:

• the deadline
• a deadline

The exact meaning comes from context. In most real situations, Rok je sutra will be understood as The deadline is tomorrow.

Je is the 3rd person singular present tense of biti (to be).

So the structure is:

• rok = deadline
• je = is
• sutra = tomorrow

Literally: Deadline is tomorrow.

This is a very normal Serbian sentence pattern.

Because the sentence is not really describing a future action. It is stating a fact about the deadline’s date.

English does the same thing:

• The deadline is tomorrow.

Serbian also uses the present of to be here:

• Rok je sutra.

So this is not strange or unusual grammar—it matches English quite closely.

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

The basic dictionary form is:

• rok — masculine noun

In Rok je sutra, rok is the thing being talked about, so nominative is exactly what you would expect.

Because sutra is normally treated as an adverb meaning tomorrow.

Adverbs do not change for case, gender, or number. So sutra stays sutra.

That is different from nouns and adjectives, which often do change endings in Serbian.

Yes. Serbian word order is fairly flexible.

These are both possible:

• Rok je sutra.
• Sutra je rok.

The basic meaning stays the same, but the emphasis changes a little:

• Rok je sutra. → focuses first on the deadline
• Sutra je rok. → focuses first on tomorrow

The first version is very natural as a neutral statement.

In a full standard sentence, you normally keep je:

• Rok je sutra.

Leaving it out can sound incomplete unless you are writing very informally, making a note, or using a headline style, for example:

• Rok sutra!

So for normal learning and standard usage, it is best to use je.

A simple learner-friendly pronunciation guide would be:

• Rok ≈ rok
• je ≈ yeh
• sutra ≈ SOO-tra

A few pronunciation notes:

• j in Serbian sounds like English y
• r is tapped or rolled, not the English r
• vowels are usually clear and pure, not diphthongs

So the whole sentence is approximately: rok yeh SOO-tra

Yes, rok is very common and natural for deadline.

You may also see:

• krajnji rok = final deadline / final due date

So:

• Rok je sutra. = The deadline is tomorrow.
• Krajnji rok je sutra. = The final deadline is tomorrow.

Both are correct, but rok by itself is often enough when the context is clear.