Džem je u maloj staklenci na polici.

Because je is a clitic in Croatian. Clitics are short unstressed words, and they normally go in second position in the sentence or clause.

So in Džem je u maloj staklenci na polici, the first element is Džem, and je comes right after it.

You will often see this with forms of biti in the present tense:

• Knjiga je na stolu.
• Mlijeko je u hladnjaku.

Even if the word order changes, je usually still stays in second position:

• Na polici je džem u maloj staklenci.

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

The basic dictionary form is also džem. It is a masculine inanimate noun.

So here:

• džem = nominative singular
• it is the thing being located

Because after u meaning in, when you are talking about location and not movement, Croatian uses the locative case.

So:

• dictionary form: mala staklenka
• after u for location: u maloj staklenci

Both words change because the adjective must agree with the noun:

• mala → maloj
• staklenka → staklenci

This is the same idea as:

• u velikoj kući
• u staroj školi

For the same reason: na also takes the locative when it means a static location, here on the shelf.

So:

• dictionary form: polica
• locative singular: polici
• with preposition: na polici

The sentence gives two layers of location:

• u maloj staklenci = in the small jar
• na polici = on the shelf

Here the difference is very literal:

• u = in / inside
• na = on

So the jam is:

• in the jar
• the jar is on the shelf

Croatian often uses u for being inside something enclosed and na for being on a surface.

Because adjectives must agree with the noun they describe in gender, number, and case.

The noun staklenka is:

• feminine
• singular
• locative here

So the adjective must also be feminine singular locative:

• mala staklenka → nominative
• u maloj staklenci → locative

So maloj is simply the feminine singular locative form of mali.

These are regular case changes for feminine nouns ending in -a.

• staklenka → staklenci
• polica → polici

With staklenka, the k changes to c before the locative ending. This kind of consonant change is common in Croatian.

Compare:

• ruka → ruci
• majka → majci
• staklenka → staklenci

So this is not random; it is part of the normal declension pattern.

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

So džem, staklenci, and polici appear without articles. Whether English uses the or a depends on context and translation, but Croatian does not mark that with separate words.

That is why a Croatian sentence can often correspond to English versions like:

• the jam
• a jam
• the shelf
• a shelf

depending on context.

Because the sentence describes where something is, not where something is going.

Croatian often uses this contrast:

• locative = location
• accusative = direction / movement toward

So:

• Džem je u maloj staklenci. = location
• Stavio sam džem u malu staklenku. = movement into

And:

• Džem je na polici. = location
• Stavio sam staklenku na policu. = movement onto

That is a very important pattern to learn with u and na.

Yes, Croatian word order is more flexible than English, but the emphasis changes.

The original sentence sounds neutral:

• Džem je u maloj staklenci na polici.

You could also say:

• Na polici je džem u maloj staklenci.

That puts more focus on na polici.

What usually stays the same is the clitic rule: je tends to remain in second position.

So Croatian word order is flexible, but not completely free.

In normal understanding, it describes the whole situation: the jam is in a small jar, and that jar is on the shelf.

In practice, listeners understand that:

• the jam is located in the jar
• the jar is on the shelf

So na polici is most naturally connected with the jar as the container holding the jam.

Croatian often stacks location phrases like this very naturally.

Dž is pronounced like the j in jam or judge.

So džem sounds close to English jem.

A rough pronunciation of the whole sentence is:

• džem ye oo MA-loy sta-KLEN-tsee na po-LEE-tsee

A few useful pronunciation points:

• j in Croatian sounds like English y in yes
• je sounds roughly like ye
• c sounds like ts
• stress is not usually marked in normal writing

So:

• je = roughly ye
• staklenci ends with a tsi sound
• polici also ends with tsi