Sutra idemo iz Zagreba u Split.

In Croatian, the present tense is very often used for a planned or arranged future action, especially when there is a time word like sutra (tomorrow).

So Sutra idemo... literally uses present tense, but it naturally means Tomorrow we’re going... or Tomorrow we go...

This is very common and natural in Croatian. You could also make the future more explicitly with ćemo, but here the present tense sounds very normal.

Croatian often drops subject pronouns when they are already clear from the verb ending.

The ending -mo in idemo tells you the subject is we.

So:

• idem = I go
• ideš = you go
• ide = he/she/it goes
• idemo = we go
• idete = you (plural/formal) go
• idu = they go

Because idemo already means we go / we are going, adding mi (we) is usually unnecessary unless you want emphasis.

Croatian word order is fairly flexible, and putting sutra first is very natural because it sets the time right away.

So Sutra idemo iz Zagreba u Split sounds like:

• Tomorrow, we’re going from Zagreb to Split.

You can also say:

• Idemo sutra iz Zagreba u Split.

That is also correct, but the version with sutra first often sounds a little smoother when you want to frame the whole sentence with the time.

This is because the two prepositions require different cases and express different meanings:

• iz = from / out of, and it takes the genitive
• u = to / into (when showing movement), and it takes the accusative

So:

• iz Zagreba = from Zagreb
  (Zagreb changes to the genitive form Zagreba)

• u Split = to Split
  (Split here is in the accusative, which happens to look the same as the basic form)

This is a very important Croatian pattern:

• iz + genitive
• u + accusative for movement

Because they are in different cases, and different nouns change in different ways.

Zagreb → Zagreba

After iz, you need the genitive:

• iz Zagreba = from Zagreb

Split → Split

After u with movement, you need the accusative:

• u Split = to Split

For many masculine inanimate nouns, the accusative singular is the same as the nominative singular.
That is why Split does not change in form here.

So the difference is not random:

• Zagreb changes because it is in the genitive
• Split looks unchanged because its accusative matches the base form

For most cities in Croatian, you use u.

So:

• u Zagreb
• u Split
• u Rijeku
• u Osijek

The preposition na is used in other situations, such as:

• with many islands: na Hvar, na Brač
• with surfaces or events
• with some locations that simply have to be learned as fixed expressions

So for a city like Split, u Split is the normal choice.

Yes, that is grammatically correct.

Sutra ćemo ići iz Zagreba u Split also means Tomorrow we will go from Zagreb to Split.

But in everyday Croatian, Sutra idemo iz Zagreba u Split often sounds more natural if the trip is already planned. The simple present is very common for near-future arrangements.

So both are possible, but:

• Sutra idemo... = very natural, common, often preferred
• Sutra ćemo ići... = also correct, a bit more explicitly future

Not exactly.

• ići = to go
• putovati = to travel

So:

• Sutra idemo iz Zagreba u Split = Tomorrow we’re going from Zagreb to Split
• Sutra putujemo iz Zagreba u Split = Tomorrow we’re traveling from Zagreb to Split

Both can work, but idemo is very common and neutral. Putujemo focuses a bit more on the fact that it is a journey or trip.

Yes. Croatian word order is flexible, as long as the grammar stays correct.

For example, these are possible:

• Sutra idemo iz Zagreba u Split.
• Idemo sutra iz Zagreba u Split.
• Iz Zagreba idemo sutra u Split.

They all mean basically the same thing, but the emphasis changes slightly depending on what comes first.

The version you were given is a very natural neutral sentence.

It is in the accusative singular, because u shows movement toward a place.

Compare:

• u Split = to Split → accusative
• u Splitu = in Split → locative

This is a key Croatian contrast:

• u + accusative = motion/destination
• u + locative = location

So:

• Idemo u Split. = We’re going to Split.
• Smo u Splitu. = We are in Split.

Because iz is a very common preposition meaning from, out of, or from inside.

It almost always takes the genitive case. So when you see:

• iz Zagreba
• iz kuće
• iz škole

you should expect the meaning from Zagreb, from the house, from school, etc.

This is one of the most useful case-preposition combinations to memorize early:

• iz + genitive

Because they are still proper names.

In Croatian, proper nouns stay capitalized in all cases:

• Zagreb
• iz Zagreba
• u Zagrebu

The ending may change because of case, but the word is still the name of a city, so it keeps its capital letter.