U torbi imam jedan bombon za nećakinju, ali joj neću dati slatkiš prije ručka.

Because u means in here, so it expresses location, and Croatian uses the locative case after u for location.

• torba = bag
• u torbi = in the bag

A useful contrast:

• u torbi = in the bag, inside the bag
• u torbu = into the bag

So:

• Imam nešto u torbi = I have something in the bag
• Stavljam nešto u torbu = I am putting something into the bag

Yes, jedan can be left out.

• imam bombon = I have a candy
• imam jedan bombon = I have one candy

Here jedan emphasizes the number one, or simply makes the sentence a bit more specific. English often uses a, but Croatian has no direct equivalent of the indefinite article, so sometimes jedan can feel a little like a/one, depending on context.

Bombon is the direct object of imam, so it is in the accusative case.

However, bombon is a masculine inanimate noun, and for many masculine inanimate nouns, the nominative and accusative singular look the same.

So:

• nominative: bombon
• accusative: bombon

That is why there is no visible change.

Because za meaning for takes the accusative case.

The base form is:

• nećakinja = niece

In the accusative singular, it becomes:

• nećakinju

So:

• za nećakinju = for my niece / for the niece

This is a very common pattern:

• za prijatelja = for a friend
• za sestru = for a sister
• za dijete = for a child

Joj means to her.

It is the unstressed dative pronoun:

• joj = to her

In this sentence, it refers back to nećakinju. So the idea is:

• neću joj dati = I will not give her

Croatian often uses these short pronouns instead of repeating the noun.

Because joj is the normal clitic form, the short unstressed form used inside a sentence.

Compare:

• joj = short, unstressed, very common in normal sentences
• njoj = full, stressed form, used for emphasis or contrast

So:

• Neću joj dati slatkiš. = normal, neutral
• Neću dati slatkiš njoj. = I will not give the sweet to her specifically

A learner can usually think of joj as the default choice unless there is emphasis.

Because joj is a short unstressed pronoun, and Croatian likes these short forms near the beginning of the clause.

So ali joj neću dati sounds very natural.

Croatian word order is more flexible than English, but clitic pronouns such as mi, ti, mu, joj, nam, vam, im usually appear early in the clause.

That is why this order feels idiomatic:

• ali joj neću dati slatkiš prije ručka

Other word orders may be possible, but they often sound less neutral or shift emphasis.

This is the normal Croatian future tense.

It is formed with a future form of htjeti plus the infinitive:

• ću dati = I will give
• neću dati = I will not give

Here:

• ću comes from htjeti
• dati is the infinitive to give

In the negative, neću is written as one word in standard Croatian.

So:

• dat ću = I will give
• neću dati = I will not give

This is about aspect, which is very important in Croatian.

• dati = perfective, a single completed act of giving
• davati = imperfective, repeated or ongoing giving

In this sentence, the speaker means one specific future act:

• I will not give her a sweet before lunch

That is why dati is the natural choice.

If you used davati, it would suggest something more habitual or repeated, like I don’t give her sweets before lunch or I won’t be giving her sweets before lunch in a broader sense.

Yes, they are related but not exactly identical.

• bombon = a candy, usually a specific type of sweet
• slatkiš = a sweet, candy, treat; a broader word

Here slatkiš is being used more generally to refer back to the bombon. This avoids repeating the same noun and sounds natural.

So the sentence is not strange. It is like saying in English:

• I have a candy in my bag for my niece, but I won’t give her the sweet before lunch.

You could also repeat bombon, but slatkiš sounds a little more general and stylistically smoother.

Because prije meaning before takes the genitive case.

The base form is:

• ručak = lunch

In the genitive singular, it becomes:

• ručka

So:

• prije ručka = before lunch

This pattern is very common:

• prije škole = before school
• prije posla = before work
• prije večere = before dinner

Because the two parts refer to different times.

• imam = I have, right now
• neću dati = I will not give, later

So the speaker is saying:

• right now, the candy is in the bag
• later, before lunch, the speaker will not give it

This mix of present and future is completely normal.

A native English speaker often notices these right away.

• ć is a softer sound than č
• č is harder, more like ch in church
• nj is like the ny sound in canyon

So in this sentence:

• nećakinju has soft ć
• slatkiš has soft ć
• ručka has hard č

A rough learner-friendly guide:

• nećakinju ≈ ne-tya-kin-yu
• slatkiš ≈ slat-kish, but with a softer ć
• ručka ≈ rooch-ka, with a harder č

The exact sounds are best learned by listening, but the important thing is that ć and č are different letters and can change how a word sounds.