Djevojčica nosi malu torbu i ide prema parku.

Because torbu is the direct object of nosi (carries / is carrying), so it has to be in the accusative case.

The dictionary form is:

• mala torba = a small bag / the small bag
  
  • mala = feminine singular nominative
  • torba = feminine singular nominative

But in the sentence, the girl is carrying the bag, so Croatian changes both words:

• malu torbu = feminine singular accusative

This is very common in Croatian: the adjective must match the noun in gender, number, and case.

Because prema requires the dative case.

So:

• park = nominative
• parku = dative

After prema, you normally use dative:

• prema parku = toward the park
• prema školi = toward the school
• prema kući = toward the house

So prema park would be ungrammatical.

Djevojčica is in the nominative case because it is the subject of the sentence — the one doing the actions.

She is the one who:

• nosi = carries
• ide = goes

So the basic subject form is used:

• djevojčica = the girl / a little girl

It can mean both, depending on the object.

With torbu (bag), nosi usually means:

• carries
• sometimes is carrying

Examples:

• Nosi torbu. = She is carrying a bag.
• Nosi kaput. = She is wearing a coat.

So nositi is a broad verb that can mean carry, wear, or have on depending on context.

Because Croatian normally does not use articles.

So djevojčica can mean:

• a girl
• the girl

And malu torbu can mean:

• a small bag
• the small bag

The exact meaning depends on context. English needs articles, but Croatian usually does not.

Because Croatian often omits subject pronouns when they are not needed.

Here, the subject is already clearly stated:

• Djevojčica nosi... i ide...

So adding ona (she) would usually be unnecessary unless you want emphasis or contrast.

For example:

• Ona ide prema parku, a on prema školi.
  = She is going toward the park, and he toward the school.

In the original sentence, djevojčica already tells us who is doing the action.

The infinitive is ići = to go.

This is an important verb because its present tense forms are somewhat irregular:

• idem = I go / am going
• ideš = you go
• ide = he/she/it goes
• idemo = we go
• idete = you plural go
• idu = they go

So ide in the sentence means goes or is going.

A rough English approximation is:

• DYE-voy-chee-tsa

A few helpful sound notes:

• j is pronounced like English y
• č is like ch in church
• c is like ts in cats

So:

• djevojčica ≈ DYE-voy-chee-tsa

It is only an approximation, but it is close enough for a learner starting out.

They are similar, but not identical.

• ide prema parku = she is going toward the park
• ide u park = she is going to / into the park

So prema emphasizes direction. It does not necessarily mean she will enter the park.
u park suggests the destination more directly.

No.

• djevojčica = little girl / girl child
• djevojka = girl / young woman, and in some contexts girlfriend

So djevojčica clearly refers to a child. That is why it fits well in this sentence.

Yes, Croatian word order is more flexible than English word order, because cases show the grammatical roles.

The neutral, natural order here is:

• Djevojčica nosi malu torbu i ide prema parku.

But other orders are possible for emphasis, style, or focus.

For example:

• Djevojčica ide prema parku i nosi malu torbu.
  This is still normal, just with the actions presented in a different order.

• Malu torbu nosi djevojčica.
  This puts special emphasis on the small bag.

So yes, word order can change, but the original sentence is the most straightforward and natural for a learner.

Because they are changing into different cases, and different word types change in different ways.

In this sentence:

• mala torba → malu torbu
  This is accusative feminine singular

• park → parku
  This is dative singular

Also, adjectives and nouns do not always use the same endings. Croatian declension depends on:

• case
• gender
• number
• sometimes noun type

So it is normal that:

• mala changes to malu
• torba changes to torbu
• park changes to parku

They are all following Croatian grammar, just in different patterns.