Preselili smo se u novi kvart prošli vikend.

Preselili smo se means we moved or more literally we relocated ourselves.

It is made of three parts:

• preselili = the past active participle of preseliti (se), to move / relocate
• smo = we are, used here as part of the Croatian past tense
• se = a reflexive particle, because the verb is usually preseliti se, to move

So Croatian forms this past tense a bit differently from English. Instead of one word like moved, it uses:

• a participle: preselili
• plus the auxiliary: smo

Together: preselili smo se = we moved.

Because the usual verb for to move house / relocate is preseliti se.

In Croatian, many verbs are used with se, and the meaning is not always literally reflexive in the English sense. Here, preseliti se is just the normal way to say to move when people change where they live.

Compare:

• preseliti nešto = to move something
• preseliti se = to move oneself / to move to another home

So in this sentence, se is necessary.

Because the hidden subject is we, and the participle agrees with the gender/number of the group.

Here, preselili is:

• plural
• usually masculine plural, or mixed-gender plural

So:

• preselio sam se = I moved (male speaker)
• preselila sam se = I moved (female speaker)
• preselili smo se = we moved (all male or mixed group)
• preselile smo se = we moved (all-female group)

Croatian often leaves out the subject pronoun mi because the verb already tells you the person and number.

Because smo is a clitic, and Croatian clitics usually go in the second position of the sentence or clause.

In Preselili smo se u novi kvart prošli vikend:

• Preselili is the first element
• then the clitics come: smo se

That is why you get:

• Preselili smo se...

not normally:

• Smo preselili se...

Clitic placement is one of the trickier parts of Croatian word order. In a neutral sentence, smo and se usually appear very early, after the first stressed element.

Because u can take different cases depending on meaning:

• u + accusative = movement into / to
• u + locative = location in

Here the sentence describes movement to a new neighborhood, so Croatian uses the accusative:

• u novi kvart = to a new neighborhood

If you were talking about being located there, you would use the locative:

• u novom kvartu = in the new neighborhood

So the case changes depending on whether the idea is movement or location.

Because novi agrees with kvart.

Kvart is a masculine singular noun, and here it is in the accusative singular. For many masculine inanimate nouns, the accusative singular looks the same as the nominative singular.

So:

• nominative: novi kvart
• accusative: novi kvart

That is why both words look unchanged here.

Kvart means neighborhood, district, or part of town.

In everyday Croatian, it is a common, natural word for the area of a city where someone lives.

So:

• novi kvart = a new neighborhood

Depending on context, English might translate it as:

• neighborhood
• district
• part of town

Croatian often uses the accusative of time without a preposition for expressions like last week, last year, this morning, and so on.

So:

• prošli vikend = last weekend

This is normal Croatian usage. English needs last, but Croatian does not need a preposition like in here.

Other similar examples:

• prošli tjedan = last week
• prošli mjesec = last month
• prošle godine = last year (this one uses a different form because of the noun)

So prošli vikend is a time expression functioning on its own.

Yes, Croatian word order is flexible, although some versions sound more neutral than others.

The given sentence is natural:

• Preselili smo se u novi kvart prošli vikend.

You could also hear:

• Prošli vikend preselili smo se u novi kvart.
• U novi kvart preselili smo se prošli vikend.

The meaning stays basically the same, but the emphasis changes:

• starting with prošli vikend emphasizes when
• starting with u novi kvart emphasizes where

Even with flexible word order, the clitics such as smo and se still tend to stay near the beginning of the clause.

This is a question of aspect, which is very important in Croatian.

• preseliti se is perfective
• seliti se is imperfective

In this sentence, preselili smo se presents the move as a completed whole event:

• We moved last weekend.

By contrast, selili smo se would suggest an ongoing process, repeated action, or focus on the activity itself:

• We were moving
• We used to move
• sometimes We were in the process of moving

Since moving to a new neighborhood is a completed event here, the perfective preselili smo se is the natural choice.

Because Croatian usually drops subject pronouns when they are already clear from the verb.

In preselili smo se, the form smo already tells you the subject is we.

So Croatian does not need mi unless you want emphasis or contrast:

• Preselili smo se u novi kvart. = neutral, normal
• Mi smo se preselili u novi kvart. = We moved to a new neighborhood, maybe contrasting with someone else

This is very common in Croatian and other Slavic languages.