Imaš li žvakaću gumu? Treba mi poslije kave.

Li is a question particle. It helps turn a statement into a yes/no question.

• Imaš žvakaću gumu. = You have chewing gum.
• Imaš li žvakaću gumu? = Do you have chewing gum?

This is a very common Croatian pattern:

• Radiš li? = Are you working?
• Znaš li? = Do you know?

In everyday speech, people also sometimes ask questions just with intonation, but verb + li is a standard and very useful structure.

In Croatian, li normally comes right after the first stressed word, and in this kind of question that is usually the verb.

So:

• Imaš li žvakaću gumu? is correct.

Not:

• Li imaš žvakaću gumu?

This word order is very typical in Croatian yes/no questions:

• Možeš li mi pomoći?
• Želiš li kavu?
• Idu li oni s nama?

Because it is the direct object of the verb imati here, so it goes into the accusative case.

The dictionary/base form is:

• žvakaća guma = chewing gum

In the accusative singular:

• žvakaću gumu

Both words change because this is a feminine adjective + feminine noun phrase.

So:

• nominative: žvakaća guma
• accusative: žvakaću gumu

This is a very common pattern with feminine adjectives and nouns:

• dobra kava → dobru kavu
• hladna voda → hladnu vodu

Yes, it is a normal and standard expression.

You may also hear shorter, more casual versions in speech, such as:

• žvaka
• žvake (often used colloquially)

But žvakaća guma is clear, standard, and completely natural.

Croatian often uses trebati in an impersonal pattern for I need:

• Treba mi... = I need...
• literally, something like It is needed to me

Here mi is in the dative case and means to me / for me.

Examples:

• Treba mi voda. = I need water.
• Treba mi pomoć. = I need help.
• Treba mi odmor. = I need rest.

You may also encounter forms like Trebam pomoć, but Treba mi pomoć is extremely common and very natural.

Mi is the unstressed dative form of ja in this construction.

So:

• mi = to me / for me

In Treba mi poslije kave, the object being needed is understood from the previous sentence: the speaker means I need it after coffee.

You could expand it:

• Treba mi žvakaća guma poslije kave.
• or more naturally in context, just Treba mi poslije kave.

Because Croatian, like English, often leaves out words that are obvious from context.

First sentence:

• Imaš li žvakaću gumu?

Second sentence:

• Treba mi poslije kave.

The missing idea is it = the chewing gum.

So the full meaning is something like:

• I need it after coffee.

This kind of omission is very natural in conversation when the listener already knows what is being discussed.

Because poslije is followed by the genitive case.

Base form:

• kava = coffee

Genitive singular:

• kave

So:

• poslije kave = after coffee

This is the normal case pattern after poslije:

• poslije ručka = after lunch
• poslije škole = after school
• poslije posla = after work

It can mean either, depending on context.

Croatian does not have articles like a or the, so kave by itself does not tell you that distinction. You understand it from the situation.

In this sentence, it most naturally means:

• after having coffee
• after drinking coffee

So the phrase is functioning more like after coffee in a general everyday sense.

A rough guide:

• ž sounds like the s in measure
• v as in English v
• a like a in father
• k
• a
• ć is a soft sound, somewhat like a very мягкий ch/t sound; English does not have an exact equivalent
• u like oo in food

Very roughly: zhva-KA-chyu, though that is only approximate.

The important letters in this sentence are:

• ž in žvakaću
• ć in žvakaću
• j in poslije, which is pronounced like English y

It is perfectly normal and polite in an informal situation, especially with someone you know or someone around your age.

If you want to be more polite or address someone formally, use imate instead of imaš:

• Imate li žvakaću gumu?

You can also soften it further:

• Imate li možda žvakaću gumu? = Do you perhaps have any chewing gum?

So:

• imaš = informal singular you
• imate = formal singular or plural you

Yes. Both can mean after coffee.

• poslije kave
• nakon kave

Both are correct. Poslije often feels very common and conversational; nakon can sound a little more neutral or formal in some contexts, but both are everyday Croatian.

Yes: Croatian word order is flexible, but some orders sound more natural than others depending on emphasis.

• Treba mi poslije kave. = neutral, natural
• Poslije kave mi treba. = possible, but marked; it emphasizes after coffee
• Treba mi žvakaća guma poslije kave. = full version with the noun included

Short unstressed words like mi often come near the beginning of the sentence, which is why Treba mi... sounds so natural.