Provjerite izlaz za ukrcaj i oznaku za prtljagu.

Provjerite is the 2nd person plural imperative of provjeriti, meaning check in the sense of giving an instruction.

It is used for:

• you all check
• you check, when speaking formally to one person

So it works like a polite/public instruction, which is why it fits well in airport language.

One extra detail: this form is also identical to the present tense form you (plural/formal) check, but in a sentence like this, the meaning is clearly imperative: an instruction or command.

Croatian usually does not need subject pronouns when the verb ending already shows who is meant.

Here, provjerite already tells you the subject is:

• you all, or
• you in a formal/polite sense

So adding vi would usually be unnecessary unless you wanted special emphasis.

Because oznaku is in the accusative singular, which is used for a direct object.

The verb provjeriti takes direct objects: you check something.
In this sentence, the things being checked are:

• izlaz za ukrcaj
• oznaku za prtljagu

The dictionary form is oznaka.
Its accusative singular is oznaku.

So:

• oznaka = the label / mark / tag
• oznaku = the label / mark / tag as the object of the verb

Here za means for, and in that meaning it is followed by the accusative case.

The noun is:

• prtljaga = luggage / baggage

Its accusative singular is:

• prtljagu

So:

• oznaka za prtljagu = a tag/label for baggage

This is a very common pattern in Croatian:

• karta za vlak = ticket for the train
• vrećica za dar = bag for a gift
• oznaka za prtljagu = baggage tag

Because ukrcaj is a masculine inanimate noun, and in Croatian those nouns often have the same form in the nominative and accusative singular.

So after za, you do have the accusative, but it looks the same:

• nominative: ukrcaj
• accusative: ukrcaj

That is why you see:

• za ukrcaj

Even though the case has changed, the form itself does not.

Literally, izlaz means exit or way out, but in airport language izlaz za ukrcaj is the normal way to say boarding gate.

So Croatian is using a phrase that is a bit more literal:

• izlaz = exit/gate
• za ukrcaj = for boarding

Together, it means the gate where passengers go for boarding.

English usually says boarding gate, while Croatian often says izlaz za ukrcaj.

It refers to a baggage label/tag.

Depending on context, English might render it as:

• baggage tag
• luggage tag
• baggage label

At an airport, this is the identifying tag connected with your luggage. The exact English wording can vary a little, but the Croatian phrase is built very straightforwardly:

• oznaka = mark, label, tag
• za prtljagu = for baggage

Both are direct objects after provjerite, so both are in the accusative.

The difference is that Croatian nouns do not all show the accusative in the same way.

• oznaka is feminine, so its accusative singular changes to oznaku
• izlaz is masculine inanimate, so its accusative singular is the same as the nominative: izlaz

So both are grammatically doing the same job, but only one of them changes form visibly.

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

The version in the sentence is natural and neutral:

• Provjerite izlaz za ukrcaj i oznaku za prtljagu.

But other orders are possible for emphasis or style, for example:

• Izlaz za ukrcaj i oznaku za prtljagu provjerite.

That said, the original version sounds the most normal for a standard instruction or announcement.

Provjeriti is a perfective verb, so it suggests checking something as a complete action.

That makes sense in an instruction like this:

• check the gate
• check the baggage tag

It points to a single, completed verification.

If Croatian used the imperfective provjeravati, it would sound more like:

• checking repeatedly
• checking continuously
• making a habit of checking

For a short practical instruction, the perfective provjerite is the natural choice.

A few pronunciation points that English speakers often notice:

• prtljagu has the cluster prtlj-, which looks hard at first.
• lj in Croatian is a single sound, similar to the lli sound in some pronunciations of million, though not exactly the same.
• ukrcaj has krc, a tight consonant cluster; Croatian allows these much more easily than English does.
• c in Croatian is pronounced like ts.

A rough pronunciation guide:

• Provjerite ≈ pro-VYE-ri-te
• izlaz ≈ EEZ-laz
• ukrcaj ≈ OO-kər-tsai / OO-kr-tsai
• oznaku ≈ oz-NA-ku
• prtljagu ≈ PRT-lya-gu

You do not need to insert strong extra vowels between the consonants; Croatian speakers are comfortable with those clusters.