Kutije su u kombiju.

Kutije is the plural form of kutija, meaning box.

• kutija = box
• kutije = boxes

In this sentence, kutije is the subject, so it means the boxes or just boxes, depending on context.

Here, kutije is in the nominative plural because it is the subject of the sentence.

A useful thing to know is that kutije can also be another form in other contexts, but in this sentence the verb su shows that kutije is plural and functioning as the subject.

So in Kutije su u kombiju, kutije = the boxes.

Su is the 3rd person plural present tense of biti (to be).

So:

• ja sam = I am
• ti si = you are
• on/ona/ono je = he/she/it is
• mi smo = we are
• vi ste = you are
• oni/one/ona su = they are

In this sentence, kutije is plural, so Serbian uses su = are.

Because su is a clitic, and clitics in Serbian usually go in the second position of the sentence or clause.

So:

• Kutije su u kombiju.
• U kombiju su kutije.

Both are possible, but su stays near the beginning, after the first main element.

This is very normal in Serbian and is one of the first word-order patterns learners notice.

Because u can take different cases depending on the meaning.

Here it means location: in the van, so Serbian uses the locative case.

• u kombiju = in the van

If you were talking about motion into the van, Serbian would use the accusative instead:

• Stavljam kutije u kombi. = I am putting the boxes into the van.

So the contrast is:

• u kombiju = in the van → location
• u kombi = into the van → movement/destination

Kombiju is in the locative singular.

The basic form is kombi. In this sentence, after u with the meaning of location, it changes to kombiju.

You can think of it like this:

• dictionary form: kombi
• locative singular: kombiju

So u kombiju literally means in the van.

Yes. Kombi is a common Serbian word, borrowed from a foreign source, and it means something like van or minibus/van-type vehicle, depending on context.

Even though it is a loanword, it behaves like a regular noun in sentences, including case forms such as:

• kombi
• kombija
• kombiju

So u kombiju is completely natural Serbian.

Because Serbian does not have articles like English a/an/the.

So:

• kutije can mean boxes or the boxes
• u kombiju can mean in a van or in the van

Context tells you which meaning is intended.

That is very common in Serbian, and English speakers often have to get used to it.

Yes. Serbian word order is more flexible than English word order.

For example:

• Kutije su u kombiju.
• U kombiju su kutije.

Both are grammatical, but the emphasis changes a little:

• Kutije su u kombiju. = neutral, starting with the boxes
• U kombiju su kutije. = emphasizes where they are

Even when the order changes, the clitic su still tends to stay in second position.

A simple pronunciation guide is:

KOO-tee-yeh soo oo KOHM-bee-yoo

A few notes:

• ku sounds like koo
• ti is like tee
• je here sounds roughly like yeh
• u is like oo
• kombiju has a y sound before the final u: bee-yoo

So kutije is roughly KOO-tee-yeh.

No, not in a normal complete sentence like this.

Since this is a sentence with to be, Serbian needs the verb:

• Kutije su u kombiju. = correct

Without su, it would sound incomplete or ungrammatical in standard Serbian.

Serbian often drops subject pronouns like oni (they), but it does not drop the verb here.

The negative is:

Kutije nisu u kombiju. = The boxes are not in the van.

Here:

• su = are
• nisu = are not

So the sentence changes very simply:

• Kutije su u kombiju.
• Kutije nisu u kombiju.