Rok popravke zavisi od rezervnog dela.

Not exactly.

In this sentence, rok means something like timeframe, period, or deadline/expected time for something to be done.

So rok popravke is closer to:

• the repair timeframe
• the repair period
• the expected repair time

By contrast, vreme is the general word for time.

So:

• vreme = time in general
• rok = a set period, deadline, or allotted time

That is why rok is a better choice here than vreme.

Because popravke is in the genitive singular.

The basic form is:

• popravka = repair

But in the phrase rok popravke, Serbian uses a noun + genitive structure, literally something like:

• timeframe of repair

So:

• popravka → nominative singular
• popravke → genitive singular

This is very common in Serbian.

Because the verb phrase is zavisiti od, which requires the genitive case.

The basic form is:

• rezervni deo = spare part

After od, it changes to genitive:

• rezervnog dela

So:

• zavisiti od nečega = to depend on something

That is why the sentence has:

• od rezervnog dela

and not od rezervni deo.

The dictionary form is:

• rezervni deo = spare part

Here is the change:

• rezervni → rezervnog
• deo → dela

Both words change because the whole noun phrase is in the genitive singular.

It comes from the verb zavisiti, which means to depend.

Here is the present tense:

• ja zavisim
• ti zavisiš
• on/ona/ono zavisi
• mi zavisimo
• vi zavisite
• oni/one/ona zavise

In your sentence, the subject is rok popravke, which is singular, so Serbian uses:

• zavisi = depends

Because that is the normal pattern in Serbian:

• zavisiti od + genitive

It corresponds to English depend on, but Serbian uses od instead of a word meaning on.

Examples:

• To zavisi od cene. = That depends on the price.
• Sve zavisi od vremena. = Everything depends on the weather/time circumstances.
• Rok popravke zavisi od rezervnog dela. = The repair time depends on the spare part.

So this is something to learn as a fixed combination:

• zavisiti od

No. Here it is genitive singular, not plural.

The noun is:

• popravka = repair

Its genitive singular is:

• popravke

That form happens to look like some other forms in Serbian, so it can be confusing. But in this sentence, it means of repair, not repairs.

Yes, Serbian word order is more flexible than English, but the given order is the most neutral and natural here:

• Rok popravke zavisi od rezervnog dela.

You might also hear:

• Od rezervnog dela zavisi rok popravke.

This puts more emphasis on the spare part.

So the original sentence is the best neutral version, while a changed word order can add emphasis.

Because Serbian does not have articles like English a and the.

So:

• rok can mean a timeframe or the timeframe
• rezervni deo can mean a spare part or the spare part

The exact meaning depends on context.

That is completely normal in Serbian.

Yes. It is a very common type of expression: a noun followed by another noun in the genitive.

This structure often corresponds to English X of Y or sometimes an adjective-like relationship.

Examples:

• cena popravke = the cost of repair
• vreme dolaska = arrival time
• rok isporuke = delivery time / delivery deadline

So rok popravke follows a very normal Serbian pattern.

Yes, that is also possible, but it is slightly different in structure.

Compare:

• rok popravke = repair timeframe / repair deadline
• rok za popravku = timeframe for repair

Both are understandable and natural in the right context. The version in your sentence is more compact and uses the noun + genitive pattern.

The noun deo is masculine singular, and its genitive singular is dela.

So:

• nominative: deo
• genitive: dela

That is why:

• rezervni deo → rezervnog dela

This is worth memorizing because deo does not form the genitive as deoa or anything similar—it becomes dela.

A simple pronunciation guide would be:

• Rok popravke zavisi od rezervnog dela
• roughly: Rok poprav-keh zah-VEE-see od reh-ZEHRV-nog DEH-lah

A few helpful notes:

• z in zavisi is like z in zoo
• š would sound like sh, but there is no š in this sentence
• c in Serbian is usually ts, but there is no c here either
• stress in Serbian is best learned by listening, but the rough guide above will help you say it understandably

Literally, it is:

• Rok popravke = timeframe of repair
• zavisi od = depends on
• rezervnog dela = spare part (genitive, after od)

So a very literal unpacking would be:

• The timeframe of repair depends on the spare part.

That literal structure helps explain why the cases are what they are:

• popravke = genitive after another noun
• rezervnog dela = genitive after od