Learn Hardcore Croatian: Osim muzeja, u našem gradu na trgu su i dva mala kazališta. - Besides the museum, in our city there are also two small theatres on the square.

the meaning is “besides the museum / in addition to the museum”.
Context makes it clear the speaker is adding information, not excluding the museum.

If you wanted the clearly “except” meaning, you would usually show it more explicitly in context, for example:

Osim muzeja, ništa drugo nema na trgu. – Except for the museum, there is nothing else on the square.

Why is it muzeja and not muzej after Osim?

Because osim is a preposition that normally takes the genitive case.

muzej – nominative (dictionary form)
muzeja – genitive singular (also genitive plural, but here we mean one museum)

So:

osim muzeja = “apart from the museum / besides the museum / except the museum”

You will see this pattern with many prepositions in Croatian, for example:

bez muzeja – without the museum (also genitive)
do muzeja – to / up to the museum (genitive)

Why is there a comma after Osim muzeja?

Osim muzeja is an introductory prepositional phrase that sets up a contrast/addition (“apart from the museum…”). In Croatian, such introductory phrases are usually separated by a comma, especially when they are a bit longer or have a strong “comment” function.

So the structure is:

[Osim muzeja], [u našem gradu na trgu su i dva mala kazališta].

Both in writing and in speech, it’s natural to have a small pause there.

Why is it u našem gradu and na trgu? Which cases are these?

Both are locative case, used with u (“in”) and na (“on / at”) when talking about location.

grad (city/town) → u našem gradu – in our town/city
- dictionary form: grad (nominative)
- locative singular: gradu → with possessive: našem gradu
trg (square) → na trgu – on the square / at the square
- dictionary form: trg
- locative singular: trgu

Croatian uses:

u + locative for “in” a place
na + locative often for “on / at” open areas, surfaces, and some public places (e.g. na trgu, na kolodvoru, na sveučilištu).

What is the nuance of trg? Does it mean “square”, “plaza”, or “market”?

Trg is primarily:

a town square, public square, or plaza – usually an open area in the center of a town, often with important buildings (city hall, church, theatre, etc.).

It can be translated as:

square (BrE) / plaza (AmE/BrE) depending on context.

If you specifically meant a market, you’d more often see words like:

tržnica, pijaca – marketplace / market (depending on region).

Why is the verb su (are) in the middle: … na trgu su i dva mala kazališta?

Croatian word order is fairly flexible. Here, the speaker starts with the location and then tells us what is there:

na trgu su i dva mala kazališta
= on the square there are also two small theatres

Placing su (the verb “to be”) after the location is very natural and common in such “there is/are at this place” statements.

You could also say:

Na trgu su dva mala kazališta. (neutral)
Dva mala kazališta su na trgu. (focus more on the theatres than on the place)

But Na trgu su i dva mala kazališta nicely emphasizes the place first and then adds the theatres as extra information.

What does the i before dva mala kazališta do? Is it just “and”?

This i is not a simple “and” joining two items; it functions more like “also / too / as well”.

… na trgu su i dva mala kazališta.
≈ … on the square there are also two small theatres.

It connects back to what was mentioned before (the museum). The idea is:

On the square there is a museum, and in addition there are two small theatres.

You could also use također for “also”:

Na trgu su također dva mala kazališta.

But i in this position is very common, short, and sounds very natural.

Why is it dva mala kazališta and not dva malo kazališta or something else?

The number dva is special:

It behaves grammatically like a numeral that requires a particular agreement pattern.

For neuter nouns like kazalište:

the noun appears in the form kazališta after dva (this form is used for several cases in neuter, so don’t worry too much about naming the case now),
the adjective usually appears in neuter plural form: mala.

So you get:

dva mala kazališta – two small theatres

Compare:

jedno malo kazalište – one small theatre
dva mala kazališta – two small theatres
mnoga mala kazališta – many small theatres

For now, the practical rule:
With dva / tri / četiri + neuter noun, use -a on the adjective: dva mala sela, tri nova kazališta, etc.

Why does kazalište change to kazališta in dva mala kazališta?

Because kazalište is a neuter noun, and its stem behaves like this:

singular
- nominative: kazalište – theatre
- genitive: kazališta, etc.
plural
- nominative: kazališta – theatres
- genitive: kazališta, etc.

So the form kazališta appears in several cases and numbers; it’s not only “plural”.

After dva, the correct form is kazališta, and you can simply memorize:

dva kazališta, tri kazališta, četiri kazališta

The important thing is: with numbers like 2–4, you do not keep the basic form kazalište; you switch to kazališta.

Why is there no word like “there is/are” (e.g. ima) and instead just su?

Croatian can express “there is/are” in two main ways:

With the verb biti (to be):
- Na trgu su dva mala kazališta. – On the square there are two small theatres.
With the verb imati in the impersonal form ima:
- Na trgu ima dva mala kazališta. – There are two small theatres on the square.

Both are possible in many contexts. Subtle differences:

su (biti) tends to sound a bit more neutral/descriptive, often used when you’re listing what is located somewhere.
ima can feel a bit more like “there exists / there is available”, sometimes a bit more informal.

In your sentence, su is perfectly natural and slightly more textbook-style.

Could I change the order to Na trgu u našem gradu su i dva mala kazališta? Does it sound okay?

Yes, that is also grammatical and natural:

Na trgu u našem gradu su i dva mala kazališta.

The difference is very small.

U našem gradu na trgu…
– slight focus on “in our town, on the square (the main square of that town)”, starting from “our town” as the larger context.
Na trgu u našem gradu…
– slight focus on “on the square (which is in our town)”, starting from the square.

In everyday speech, both are fine and will usually be understood the same way.

What is the difference between kazalište and kino? Both can be translated as “theatre,” right?

In Croatian:

kazalište = theatre (live stage performances: plays, drama, opera, ballet…)
kino = cinema, movie theatre (you go there to watch films)

So dva mala kazališta means two small theatres (for plays, etc.), not two cinemas. If you meant cinemas, you would say:

dva mala kina – two small cinemas.

Is there any difference between u našem gradu na trgu su i dva mala kazališta and just Na trgu su i dva mala kazališta?

The difference is only that u našem gradu adds which town/city we are talking about.

Na trgu su i dva mala kazališta.
– On the square there are also two small theatres. (Square of some town; context must tell you which.)
U našem gradu na trgu su i dva mala kazališta.
– In our town, on the square, there are also two small theatres. (Now you know it’s our town’s square.)

Grammatically they’re the same type of sentence; u našem gradu just narrows down the location.