Dječak voli romobil, dok djevojčica radije trči po livadi.

Yes, romobil is in the accusative here.

The important point is that in Croatian, masculine inanimate nouns often have the same form in the nominative and accusative singular.

• nominative: romobil = a scooter / the scooter as subject
• accusative: voli romobil = likes the scooter as object

So even though the form does not change, its function does:

• Romobil je brz. = The scooter is fast. → subject
• Dječak voli romobil. = The boy likes the scooter. → object

This is very common in Croatian.

Both are in the nominative singular because they are the subjects of their clauses.

• Dječak voli romobil.
• djevojčica radije trči po livadi.

So:

• dječak = nominative singular masculine
• djevojčica = nominative singular feminine

A useful way to see the sentence structure is:

• Dječak = subject
• voli = verb
• romobil = object

and

• djevojčica = subject
• radije trči = verb phrase
• po livadi = prepositional phrase

Here dok means while, whereas, or while on the other hand.

It connects two clauses and creates a contrast:

• Dječak voli romobil
• dok djevojčica radije trči po livadi

So the idea is not just that both things happen, but that the two preferences are being compared.

In other contexts, dok can also mean until, but not here.

Examples:

• Čekaj dok dođem. = Wait until I come.
• On čita, dok ona piše. = He is reading, while she is writing.

In your sentence, it is clearly the second meaning: while/whereas.

Radije means rather, preferably, or would rather.

In this sentence, it shows preference:

• djevojčica radije trči po livadi = the girl prefers to run across the meadow / would rather run in the meadow

It is the comparative form of rado, which is related to doing something gladly or willingly.

A useful mini-pattern:

• rado = gladly
• radije = rather / preferably
• najradije = most gladly / most of all

Examples:

• Rado čitam. = I gladly read / I like reading.
• Radije čitam nego gledam TV. = I’d rather read than watch TV.
• Najradije spavam. = What I like most is sleeping / I’d most like to sleep.

Croatian often expresses preference very naturally with radije + verb.

So:

• radije trči literally means something like runs rather / would rather run
• natural English translation: prefers to run or would rather run

This is a very common and idiomatic Croatian structure.

Compare:

• Ona radije hoda. = She prefers walking / She would rather walk.
• Ja radije ostajem kod kuće. = I prefer staying at home.

Croatian can also express preference in other ways, but radije + present-tense verb is one of the most common everyday patterns.

Because trči is the conjugated verb form, while trčati is the infinitive.

• trčati = to run
• trči = he/she runs

In the sentence, the subject is djevojčica (the girl), so the verb must agree with a third-person singular subject:

• djevojčica trči = the girl runs

A few present-tense forms of trčati:

• ja trčim = I run
• ti trčiš = you run
• on/ona trči = he/she runs
• mi trčimo = we run
• vi trčite = you run
• oni/one trče = they run

Voli is the third-person singular present tense of voljeti (to like / to love).

Since the subject is dječak (the boy), you need the form that means he likes:

• dječak voli = the boy likes

Basic forms:

• ja volim = I like
• ti voliš = you like
• on/ona voli = he/she likes
• mi volimo = we like
• vi volite = you like
• oni/one vole = they like

So voli matches dječak correctly.

Because Croatian has no articles.

English uses:

• a
• an
• the

Croatian does not have direct equivalents. So:

• dječak can mean a boy or the boy
• djevojčica can mean a girl or the girl
• romobil can mean a scooter or the scooter

The exact meaning depends on context.

That is why one Croatian sentence can often be translated into English in more than one valid way.

Because po and na do not mean the same thing.

po livadi

This suggests movement around, over, or across an area:

• trčati po livadi = to run around/on/across the meadow

na livadi

This usually means being on the meadow or doing something there:

• biti na livadi = to be in/on the meadow
• igrati se na livadi = to play in the meadow

So in your sentence, po livadi fits well because the girl is running around the meadow, not just located there.

Livadi is in the locative singular.

The preposition po normally takes the locative when it has the sense seen here:

• po livadi = around the meadow / across the meadow

The base noun is:

• livada = meadow

Locative singular:

• livada → livadi

This is a common feminine noun pattern:

• škola → u školi
• soba → u sobi
• livada → po livadi

So the ending -i tells you the noun is in the locative singular.

Not exactly. A very literal translation can be misleading.

Po often has the sense of:

• around
• over
• across
• all over

So trči po livadi gives the image of someone moving throughout the meadow area.

In natural English, depending on context, you might translate it as:

• runs in the meadow
• runs across the meadow
• runs around the meadow

All of these can be reasonable, but the Croatian wording emphasizes movement within that area, not just simple location.

Because dok introduces another clause, and Croatian normally separates such clauses with a comma.

So the sentence has two parts:

1. Dječak voli romobil
2. dok djevojčica radije trči po livadi

The comma helps show the pause and the contrast between the two ideas.

This is very normal in Croatian punctuation.

Yes, Croatian word order is more flexible than English word order, although some versions sound more natural than others.

The original:

• Dječak voli romobil, dok djevojčica radije trči po livadi.

You may also hear:

• Dječak voli romobil, dok djevojčica po livadi radije trči.
• Dok djevojčica radije trči po livadi, dječak voli romobil.

But the original version is the most straightforward and natural for a learner.

Why? Because it keeps:

• subject first
• verb early
• contrast clear

So yes, word order can move, but Croatian speakers choose word order to manage focus, emphasis, and style.

A rough pronunciation guide:

• dječak ≈ dye-chaak
• djevojčica ≈ dye-VOY-chee-tsa
• trči ≈ tr-chee
• livadi ≈ lee-VA-dee

A few important sounds:

• č = like ch in church, but usually a bit firmer
• ć = also a kind of ch sound, but softer; English speakers often find č and ć hard to distinguish at first
• c = ts as in cats
• lj = similar to the lli in million for many learners
• dj / đ-type sounds can be tricky and vary depending on the exact spelling and dialect

You do not need perfect pronunciation immediately, but learning the special Croatian letters early is very helpful.

Yes, it has a diminutive feel in form.

• djevojka = girl, young woman
• djevojčica = little girl / girl

In many contexts, though, djevojčica is simply the normal word for girl in the sense of a child, so learners should not overthink the diminutive idea every time they see it.

Similarly:

• dječak = boy

So in this sentence, djevojčica is best understood simply as girl.

Sometimes, yes, in a loose sense.

Because the sentence is contrasting two preferences, English might naturally say:

• The boy likes the scooter, but the girl prefers running in the meadow.

That is not a word-for-word translation, but it can sound natural.

Still, the core meaning of dok here is closer to:

• while
• whereas

So but can work in translation if you want a smooth English sentence, but it is not the most direct equivalent.

It is basically:

[Subject] + [verb] + [object], dok [subject] + [adverb] + [verb] + [prepositional phrase].

So here:

• Dječak = subject
• voli = verb
• romobil = object

then

• dok = connecting word meaning while/whereas
• djevojčica = subject
• radije = adverb of preference
• trči = verb
• po livadi = prepositional phrase

This is a very useful kind of sentence for learners because it combines:

• subject-verb agreement
• accusative object
• adverb usage
• a contrast connector
• a preposition with the locative case