Osim stanarine, svaki mjesec plaćamo i pričuvu za zgradu.

Here osim means apart from, besides, or in addition to.

In this sentence, it introduces something that is added to the main expense:

• Osim stanarine... = Besides the rent...

A very important grammar point: osim normally takes the genitive case.

Because stanarina is after osim, and osim usually requires the genitive.

The noun is:

• nominative: stanarina
• genitive: stanarine

So:

• osim stanarine = besides the rent

This is a very common pattern in Croatian:

• osim škole
• osim posla
• osim stanarine

It is built into the verb plaćamo.

Croatian usually does not need a separate subject pronoun if the verb ending already shows who is doing the action.

• plaćam = I pay
• plaćaš = you pay
• plaća = he/she/it pays
• plaćamo = we pay
• plaćate = you pay
• plaćaju = they pay

So plaćamo already means we pay.

You could say mi plaćamo, but mi would usually add emphasis or contrast:

• Mi plaćamo, a oni ne. = We pay, but they don’t.

Plaćamo is the 1st person plural present tense form of the imperfective verb plaćati.

So it means:

• we pay
• we are paying
• in this context, more naturally: we pay regularly / habitually

Because the sentence says svaki mjesec (every month), Croatian uses the imperfective verb very naturally here for a repeated action.

Compare:

• plaćati = to pay, to be paying, to pay regularly
• platiti = to pay completely, to make a completed payment

Here plaćamo is better because the sentence describes a recurring monthly obligation.

In this sentence, i means also or too.

Croatian often puts i directly before the word or phrase it is adding.

So:

• plaćamo i pričuvu = we also pay the reserve fee

The idea is:

• besides the rent,
• we also pay pričuva

This is different from English, where too often comes at the end:

• We pay a reserve fee too.

In Croatian, i usually comes earlier, before the added element.

Pričuva is a housing/building-management term.

In everyday Croatian, it usually means a reserve fund contribution or building maintenance reserve for an apartment building. It is money paid regularly for shared building costs, maintenance, repairs, and similar expenses.

Grammatically, here it appears as pričuvu because it is the direct object of plaćamo:

• nominative: pričuva
• accusative: pričuvu

So:

• plaćamo pričuvu = we pay the reserve fund contribution

Zgradu is in the accusative singular.

The noun is:

• nominative: zgrada = building
• accusative: zgradu

That is because the preposition za here takes the accusative:

• za zgradu = for the building

So this phrase explains what the reserve fund is for:

• pričuvu za zgradu = reserve money / reserve fee for the building

Yes, you can also say svakog mjeseca.

Both:

• svaki mjesec
• svakog mjeseca

can mean every month.

In this sentence, svaki mjesec is a very natural time expression and is common in everyday language.

Very roughly:

• svaki mjesec = every month
• svakog mjeseca = every month

In many situations, the difference is small or nonexistent for practical purposes.

Because Croatian has no articles.

There is no separate word for:

• a
• an
• the

So zgrada or zgradu can mean:

• a building
• the building

The exact meaning comes from context. In this sentence, English naturally uses the building, but Croatian does not need a word for that.

Yes. Croatian word order is fairly flexible because case endings show the grammatical roles.

The original sentence is natural and clear:

• Osim stanarine, svaki mjesec plaćamo i pričuvu za zgradu.

But other orders are possible, depending on emphasis, for example:

• Svaki mjesec, osim stanarine, plaćamo i pričuvu za zgradu.
• I pričuvu za zgradu plaćamo svaki mjesec, osim stanarine.
  This is possible, but much more marked and less neutral.

One important detail: moving i can change what is being emphasized as also.

Yes, stanarina is a common everyday word for rent, especially for an apartment or place to live.

Another word you may also see is najamnina, which is more general and can sound a bit more formal or legal depending on context.

So in everyday speech:

• stanarina is very natural here

In this sentence:

• Osim stanarine... = Besides the rent...