Ako je tvoje odredište Zagreb, moraš izaći na sljedećoj stanici.

Ako means if.

The sentence has two parts:

• Ako je tvoje odredište Zagreb = If your destination is Zagreb
• moraš izaći na sljedećoj stanici = you must get off at the next stop/station

So this is a normal if-clause + main clause structure.

This is a very common Croatian word-order feature.

Je is a short form of biti (to be), and short forms like this are clitics. In Croatian, clitics usually go in the second position in their clause.

So:

• Ako je tvoje odredište Zagreb is natural
• Ako tvoje odredište je Zagreb sounds unnatural in standard Croatian

Even though English would normally put is after the subject, Croatian often places je early because of this clitic rule.

Because odredište is a neuter singular noun.

The possessive pronoun tvoj changes to agree with the noun:

• tvoj = masculine singular
• tvoja = feminine singular
• tvoje = neuter singular

Since odredište is neuter, you need tvoje odredište.

Odredište means destination.

It comes from the verb odrediti (to determine / specify) historically, but as a noun it simply means the place you are headed to.

Examples:

• Konačno odredište = final destination
• Moje odredište je Split = My destination is Split

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

So where English says:

• the destination
• a station
• the next stop

Croatian just uses the noun by itself, and the meaning is understood from context.

That is why you get:

• tvoje odredište Zagreb not something like the Zagreb

Moraš means you must or you have to.

It is the 2nd person singular present form of morati (to have to / must).

Forms of morati include:

• moram = I must
• moraš = you must
• mora = he/she/it must
• moramo = we must
• morate = you must (plural/formal)
• moraju = they must

So here the speaker is talking to one person informally: moraš.

Because Croatian modal verbs are normally followed by an infinitive.

So:

• moraš izaći = you must get off / go out
• mogu doći = I can come
• želim vidjeti = I want to see

This is similar to English must go, can come, want to see.

Here:

• moraš = modal verb
• izaći = infinitive

Literally, izaći means to go out / to exit.

But in transport contexts, it very often means:

• get off
• get out
• exit

So in this sentence, moraš izaći na sljedećoj stanici means you must get off at the next stop/station.

It is the natural verb to use for leaving a bus, tram, train, etc.

It is locative singular.

• stanica = a feminine noun
• na here means at / on
• after na, Croatian can use either accusative or locative, depending on meaning

Here the phrase means at the next stop/station, so it uses the locative:

• na sljedećoj stanici

This is the normal way to say at the next stop in this kind of travel situation.

Because sljedećoj has to agree with stanici.

The noun stanica is:

• feminine
• singular
• here in the locative

So the adjective sljedeći (next / following) must match it:

• nominative feminine singular: sljedeća stanica
• locative feminine singular: na sljedećoj stanici

That -oj ending is the normal feminine singular dative/locative adjective ending.

Because the noun changes case.

The basic form is:

• stanica = nominative singular

But after na in this expression, you need the locative singular:

• na stanici = at the station / at the stop
• na sljedećoj stanici = at the next stop

So:

• stanica = dictionary form
• stanici = locative singular form

It can mean either, depending on context.

In transport Croatian, stanica often means:

• stop for buses, trams, etc.
• station in some other contexts

In this sentence, English would often translate it as stop:

• You must get off at the next stop

But station is not wrong if the context is a train or similar system. The exact English choice depends on the situation.

Yes. It is addressing one person informally.

• tvoje = your (informal singular)
• moraš = you must (informal singular)

If you were speaking formally or to more than one person, you would say:

Ako je vaše odredište Zagreb, morate izaći na sljedećoj stanici.

So:

• tvoje / moraš = informal singular
• vaše / morate = formal singular or plural

Yes, that is possible.

Croatian word order is more flexible than English, so both of these are grammatical:

• Ako je tvoje odredište Zagreb
• Ako je Zagreb tvoje odredište

The difference is mostly about emphasis and style, not basic meaning.

The original version sounds very natural and neutral. The version with Zagreb earlier may put a bit more focus on Zagreb.

Because the sentence begins with a subordinate if-clause.

• Ako je tvoje odredište Zagreb, = subordinate clause
• moraš izaći na sljedećoj stanici. = main clause

In Croatian, it is normal to separate these with a comma, just as in English:

• If your destination is Zagreb, you must get off at the next stop.

So the comma is standard punctuation here.