Uredit ću dnevni boravak prije nego što dođu gosti.

The infinitive is urediti. In Croatian future tense, when the auxiliary ću comes after an infinitive ending in -ti, the final -i is dropped in writing:

• urediti
  • ću → uredit ću

If the auxiliary comes before the infinitive, the full infinitive stays:

• ću urediti

So uredit ću is the normal form here.

Uredit ću is Future I, the normal future tense.

Yes, ću urediti is also grammatically correct, but ću is a clitic, so it normally cannot stand at the very beginning of a sentence by itself. That is why sentence-initial Uredit ću... sounds natural, while Ću urediti... does not.

A correct example with ću urediti would be:

• Sutra ću urediti dnevni boravak.

Urediti is a perfective verb. It presents the action as something completed, with a result.

That fits this sentence well, because the speaker wants the living room to be in order before the guests arrive. The focus is on finishing the task.

An imperfective verb such as uređivati would suggest an ongoing, repeated, or process-like action, which is not the main idea here.

Here urediti means something like put in order, tidy up, arrange, or fix up, depending on context.

With dnevni boravak, it usually suggests making the living room look presentable or organized. It does not have to mean only cleaning; it can also include arranging or preparing the room.

Dnevni boravak is the normal Croatian expression for living room.

Literally, the parts are:

• dnevni = daily, daytime
• boravak = stay, being somewhere

But together they form a fixed expression meaning living room.

In this sentence it is the direct object of urediti, so it is in the accusative singular. However, because boravak is a masculine inanimate noun, its accusative singular looks the same as its nominative singular, so the form does not change.

Prije nego što means before and introduces a subordinate clause.

Yes, prije nego is also common and often acceptable. But prije nego što is very standard and explicit, so it is a very good form for learners to know and use.

After time expressions like prije nego što, Croatian often uses the present tense of a perfective verb to talk about a future event.

So dođu is literally a present-tense form, but here it refers to the future: the guests’ arrival.

This is similar to English, which also says:

• before the guests come

not

• before the guests will come

So the Croatian structure is very natural here.

Dođu is the 3rd person plural present form of the perfective verb doći.

Its present forms are:

• dođem
• dođeš
• dođe
• dođemo
• dođete
• dođu

So dođu means they come / they arrive, but in this sentence it has future meaning because of the time clause.

Gosti is nominative plural, because it is the subject of dođu.

The singular form is gost.

A useful comparison:

• gosti dolaze = the guests are coming
• vidim goste = I see the guests

In the second example, goste is accusative plural, not nominative.

Yes. Croatian word order is fairly flexible.

For example, you can also say:

• Prije nego što dođu gosti, uredit ću dnevni boravak.

That version sounds just as natural.

Inside the subordinate clause, both dođu gosti and gosti dođu are possible. The difference is mostly one of emphasis, rhythm, or style rather than basic meaning.

For an English speaker:

• ć in ću is a very soft consonant, somewhere between English t and ch
• đ in dođu is a soft j/dj sound, similar to the j in juice, but softer

Very rough approximations:

• ću ≈ tyoo
• dođu ≈ DO-joo

Those are only approximations, but they are close enough to help you get started.