Priložite presliku dokumenta uz prijavu.

Because it is the formal or plural imperative of the verb priložiti.

In Croatian, -te is commonly used for:

• you plural commands
• formal singular commands, when speaking politely to one person

So Priložite means Attach / Enclose ... said politely or to more than one person.

Compare:

• Priloži = attach! (to one person, informal)
• Priložite = attach! (formal singular or plural)

It comes from the verb priložiti.

This verb commonly means:

• to attach
• to enclose
• to include (especially with applications, forms, letters, and documents)

In administrative or formal Croatian, priložiti is very common in instructions like:

• Priložite fotografiju.
• Priložite dokaz o uplati.

It sounds more official than a very general verb like staviti (to put).

Because priložiti takes a direct object, and direct objects are usually in the accusative.

Here, the thing being attached is presliku dokumenta.

The head noun is preslika, and in this sentence it appears in the accusative singular:

• nominative: preslika
• accusative: presliku

So:

• Priložite presliku... = attach a copy...

Because preslika dokumenta means a copy of the document.

In Croatian, when one noun defines another in this of relationship, the second noun is often in the genitive.

So:

• preslika = copy
• dokumenta = of the document

This is a very common pattern:

• broj telefona = phone number
• adresa stanovanja = address of residence
• preslika putovnice = copy of the passport

So presliku dokumenta literally works like copy of the document.

Prijavu is in the accusative singular.

That is because it follows the preposition uz, which normally takes the accusative when it means with, along with, or next to.

So:

• uz prijavu = with the application / along with the application

Compare:

• nominative: prijava
• accusative: prijavu

Here uz means with, along with, or together with.

In this sentence, it tells you that the copy of the document should be submitted together with the application.

This is a very common administrative use of uz:

• Uz zahtjev priložite potvrdu. = Attach a certificate with the request.
• Uz obrazac dostavite fotografiju. = Submit a photo with the form.

Depending on context, uz can also mean next to in a physical sense, but here it clearly means along with.

Yes, very often.

Both preslika and kopija can mean copy. However:

• preslika often sounds a bit more formal or administrative
• kopija is very common in everyday language and is often the more familiar word for learners

So both are possible, but preslika dokumenta fits the official style of forms and instructions very well.

Not completely, but the given order is the most natural for an instruction.

Standard order:

• Priložite presliku dokumenta uz prijavu.

Croatian word order is flexible, so other orders are possible, for example:

• Uz prijavu priložite presliku dokumenta.

This version puts more emphasis on uz prijavu (with the application).

In formal instructions, both are acceptable, but the original sentence is straightforward and very natural.

Because Croatian does not have articles like English a/an and the.

So presliku dokumenta can mean:

• a copy of the document
• the copy of the document

The exact meaning depends on context.

In official instructions, English often uses a:

• Attach a copy of the document with the application.

But Croatian simply leaves that unstated.

Yes, very much so.

Several things make it formal:

• the imperative Priložite
• the official vocabulary priložiti
• the noun phrase presliku dokumenta
• the administrative phrase uz prijavu

This is the kind of sentence you would expect in:

• application instructions
• government forms
• school or university admissions
• visa procedures
• official correspondence

It would sound less natural in casual everyday conversation.

Yes. It sounds natural, correct, and appropriately formal.

A native speaker would easily recognize it as standard bureaucratic or administrative Croatian. You might also see very similar versions such as:

• Uz prijavu priložite presliku dokumenta.
• Molimo da uz prijavu priložite presliku dokumenta.
• Potrebno je priložiti presliku dokumenta uz prijavu.

All of these are normal in formal written Croatian.