Poslije konferencije vraćamo se u hotel.

Because poslije normally requires the genitive case.
The noun konferencija is feminine, and its genitive singular form is konferencije.

So:

• konferencija = conference
• poslije konferencije = after the conference

This is a very common pattern in Croatian: certain prepositions force a specific case, and poslije is one of them.

Poslije means after. In this sentence, it introduces a time expression: after the conference.

It is very close in meaning to nakon, and in many situations they are interchangeable:

• Poslije konferencije...
• Nakon konferencije...

Both mean after the conference.

A learner should mainly remember this:

• both usually take the genitive
• poslije is very common in everyday speech
• nakon can sound a little more formal or neutral depending on context

Because the verb here is vraćati se / vratiti se, which means to return, to go back, or to come back.

Without se, vraćati usually means to return something:

• Vraćamo knjigu. = We are returning the book.

With se, it means that the subject itself is going back:

• Vraćamo se u hotel. = We are returning to the hotel.

So se is essential here. It is part of the verb meaning.

The form vraćamo se is 1st person plural present tense: we return / we are returning.

Its dictionary form is usually given as:

• vraćati se = to be returning, to return repeatedly, to go back
• vratiti se = to return back once, to come back

In this sentence, vraćamo se comes from vraćati se, the imperfective verb.

That means it can sound like:

• we are returning
• we return
• we’re going back

depending on context.

Because Croatian distinguishes between motion toward a place and location in a place.

With u:

• u + accusative = motion into/to
• u + locative = being in

So:

• u hotel = to the hotel / into the hotel
• u hotelu = in the hotel

In this sentence, there is movement back to the hotel, so Croatian uses the accusative:

• vraćamo se u hotel

Grammatically, it is present tense, so the most direct meaning is:

• we return
• we are returning

But Croatian present tense is often broader than English present tense. Depending on context, it can also refer to a planned or immediate future action.

So this sentence could mean:

• After the conference, we return to the hotel.
• After the conference, we’re returning to the hotel.
• sometimes even After the conference, we’ll go back to the hotel.

The exact English translation depends on the situation.

Yes, Croatian word order is more flexible than English word order.

This sentence starts with the time phrase:

• Poslije konferencije = after the conference

Then comes the verb phrase:

• vraćamo se = we return
• u hotel = to the hotel

You could also say:

• Vraćamo se u hotel poslije konferencije.
• U hotel se vraćamo poslije konferencije.

These versions are still grammatical, but the emphasis changes a little.

One important rule remains: se is a clitic, so it usually has to stay near the beginning of its clause, often in the second position area. That is why you do not usually place it freely just anywhere.

Because Croatian has no articles.

English says:

• after the conference
• to the hotel

Croatian simply says:

• poslije konferencije
• u hotel

Whether something means a, an, or the is understood from context.

This is one of the biggest differences from English, so it is very normal for learners to notice it immediately.

In this sentence, hotel is in the accusative singular, but for this noun the accusative looks the same as the nominative:

• hotel = nominative singular
• hotel = accusative singular

So the form does not visibly change, even though the case does.

That is common with many masculine inanimate nouns in Croatian.

That depends on the standard and regional variety.

• poslije is standard in many Croatian contexts
• posle is common in Serbian
• poslije and posle can both be heard regionally in the wider BCMS area

If you are specifically learning standard Croatian, poslije is the safer choice.

By itself, the sentence can be understood either way, depending on context.

Because vraćamo se is from the imperfective verb vraćati se, it can be used for:

• something happening now or around now
• a regular/habitual action
• a planned action after an event

So it could mean:

• After the conference, we are going back to the hotel.
• After the conference, we usually go back to the hotel.

If you wanted to stress a single completed return more strongly in some contexts, Croatian might use the perfective verb vratiti se in another form, depending on tense and structure.

You could add the pronoun mi:

• Poslije konferencije mi se vraćamo u hotel.

But Croatian often leaves subject pronouns out, because the verb ending already shows who is doing the action:

• vraćamo = we return

So the original sentence without mi is more neutral and natural unless you want contrast, for example:

• Oni idu u restoran, a mi se vraćamo u hotel.
  They are going to the restaurant, and we are returning to the hotel.