Recepcionarka nam je pokazala dvokrevetni apartman, ali moja sestra je ipak izabrala manju jednokrevetnu sobu.

Because both verbs are in the past tense, and the subject is feminine singular in each clause.

In Croatian past tense, you usually have:

• a form of biti (je here)
• plus the so-called l-participle

So:

• recepcionarka je pokazala = the receptionist showed
• moja sestra je izabrala = my sister chose

The -la ending shows feminine singular, matching:

• recepcionarka = feminine singular
• sestra = feminine singular

If the subject were masculine, you would get pokazao / izabrao.

Nam means to us.

It is the unstressed dative form of mi (we/us). The verb pokazati often works like this:

• pokazati nešto nekome = to show something to someone

So in this sentence:

• dvokrevetni apartman = the thing that was shown
• nam = the people it was shown to

That is why Croatian uses the dative here.

This is about Croatian clitic placement.

Words like je and nam are unstressed clitics, and they usually appear near the beginning of the clause, in the so-called second position.

So:

• Recepcionarka nam je pokazala...
• ...moja sestra je ipak izabrala...

In the first clause, the clitic group nam je comes right after the first main element Recepcionarka.

In the second clause, moja sestra acts as the first phrase, and then je follows it.

This often feels unusual to English speakers, because English keeps auxiliaries and pronouns in more fixed positions.

Because both are direct objects, so they are in the accusative case, but masculine and feminine nouns behave differently.

1. dvokrevetni apartman

Apartman is masculine singular and inanimate.
For masculine inanimate nouns, the accusative usually looks the same as the nominative.

So:

• nominative: dvokrevetni apartman
• accusative: dvokrevetni apartman

2. manju jednokrevetnu sobu

Soba is feminine singular.
In the accusative singular, feminine nouns and their adjectives usually change form.

So:

• nominative: jednokrevetna soba
• accusative: jednokrevetnu sobu

And:

• nominative: manja
• accusative: manju

Because manju is the comparative form: smaller.

The adjective mali means small, but its comparative is irregular:

• mali = small
• manji = smaller

Here the sister chooses a smaller single room, not just a small one.

Since it agrees with sobu (feminine singular accusative), manji becomes manju.

So:

• manju sobu = a smaller room

Ipak means something like:

• nevertheless
• still
• after all
• even so

In this sentence, it shows contrast: the receptionist showed us a double apartment, but my sister still / nevertheless chose a smaller single room.

So ipak adds the idea that the choice went against what you might expect from the previous clause.

They are not the same kind of accommodation.

• apartman = apartment, suite, or a larger self-contained unit
• soba = room

So a dvokrevetni apartman is typically a larger place for two people, while a jednokrevetna soba is simply a single room.

This contrast is important in the sentence: the receptionist showed a more spacious option, but the sister chose a smaller single room instead.

They are built from words meaning two/one plus bed.

• krevet = bed
• dvo- = two
• jedno- = one

So:

• dvokrevetni = two-bed, meaning double or for two people
• jednokrevetni = one-bed, meaning single

In hotel language:

• dvokrevetna soba = double room
• jednokrevetna soba = single room

In your sentence, the forms change to match the nouns they describe:

• dvokrevetni apartman (masculine accusative = same as nominative)
• jednokrevetnu sobu (feminine accusative)

Because the sentence describes completed actions.

• pokazala comes from pokazati = to show (perfective)
• izabrala comes from izabrati = to choose (perfective)

The meaning is:

• the receptionist finished showing the apartment
• the sister finished making her choice

That is why perfective verbs fit well here.

If you used imperfective verbs instead, the meaning would shift toward an ongoing, repeated, or less bounded action, which would sound different from this clear sequence of completed events.

Yes, Croatian word order is fairly flexible, but not completely free.

This sentence has a very natural neutral order:

• Recepcionarka nam je pokazala...
• ...ali moja sestra je ipak izabrala...

You can move things around for emphasis, for example:

• Dvokrevetni apartman nam je pokazala recepcionarka...
• Moja sestra je ipak izabrala manju sobu.

But clitics like nam and je still have to follow Croatian clitic-placement rules, so you cannot move them just anywhere.

So the main idea is:

• content words can often move for focus or emphasis
• clitics are much more restricted

Not always, but it is very natural here.

Croatian often uses possessive words like moj, tvoj, njegov when the speaker wants to identify the person clearly or make the relation explicit.

So:

• moja sestra = my sister

You could sometimes omit the possessive if the context already makes it obvious, but keeping moja is completely normal and often sounds more natural, especially in a full sentence like this.

It also helps make the contrast clearer:

• the receptionist did one thing
• my sister did another

Ali means but.

It introduces a contrast between the two clauses:

• first, the receptionist showed a double apartment
• then, despite that, the sister chose a smaller single room

Because the sentence also includes ipak, the contrast becomes even clearer:

• ali = but
• ipak = nevertheless / still

Together they make the second clause sound like an unexpected choice.