U sustavu e-Građani koristimo potpisni certifikat za elektronički potpis.

Because u here means in/inside, so it expresses location, not movement. After u in that meaning, Croatian uses the locative case.

• basic form: sustav = system
• locative singular: sustavu

So:

• u sustavu = in the system

Compare:

• u sustavu = in the system
• u sustav = into the system

That second one would use the accusative and would suggest movement into something.

e-Građani is the name of the platform/system, like a proper name: e-Citizens.

In u sustavu e-Građani, the word sustavu changes because it is the common noun system, while e-Građani stays as the official name of that system.

You can think of it like:

• u sustavu e-Građani = in the e-Građani system

Names, brand-like labels, and titles often stay unchanged, especially when they function almost like fixed labels after another noun.

Koristimo is the 1st person plural present tense of koristiti = to use.

So literally it means:

• we use

This form is very common in Croatian not only for real we, but also in neutral, instructional, or institutional language, where English might also say:

• we use
• one uses
• the system uses
• users use

So the sentence sounds natural in official or explanatory language.

Potpisni is an adjective formed from potpis = signature.

So:

• potpis = signature
• potpisni = signature-related / used for signing

That means:

• potpisni certifikat = signature certificate or certificate used for signing

Croatian often uses adjectives like this where English might use a noun before another noun. English says signature certificate, but Croatian more naturally says potpisni certifikat, with an adjective.

Here za means for, and it expresses purpose or intended use.

So:

• za elektronički potpis = for an electronic signature

After za in this meaning, Croatian uses the accusative case. In this phrase:

• elektronički potpis is in the accusative
• but because potpis is an inanimate masculine noun, its accusative singular looks the same as the nominative

So the form does not visibly change, but grammatically it is accusative.

They are related, but they do different jobs in the sentence.

• potpisni certifikat = a certificate meant for signing
• elektronički potpis = the actual electronic signature

So the sentence is saying that in the e-Građani system, we use a signing certificate in order to create/use an electronic signature.

Even though both words come from potpis, they refer to different things:

• the certificate
• the signature

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

So a phrase like:

• potpisni certifikat

can mean, depending on context:

• a signature certificate
• the signature certificate

The exact meaning comes from context, not from an article.

This is normal in Croatian, and learners have to get used to understanding definiteness from the situation.

Not completely. Croatian word order is more flexible than English because the case endings help show grammatical relationships.

The given order:

• U sustavu e-Građani koristimo potpisni certifikat za elektronički potpis.

is natural and neutral.

But other orders are possible, for example to emphasize different parts:

• Potpisni certifikat koristimo u sustavu e-Građani za elektronički potpis.
• U sustavu e-Građani potpisni certifikat koristimo za elektronički potpis.

These all mean roughly the same thing, but the emphasis changes slightly. The original version sounds like standard informational language.

The letter đ is pronounced somewhat like the j in judge, but softer and more palatal.

So Građani is approximately:

• GRAH-jah-nee

Very roughly.

A few pronunciation notes:

• gr = as written
• a = short a, like in many European languages
• đ = soft j/dj sound
• ani = ah-nee

Also:

• ž in koristimo does not appear here, but if you see ž elsewhere, it sounds like the s in measure
• č in elektronički sounds like ch in chocolate

Possibly, depending on context, but elektronički potpis is the standard legal/technical term in many Croatian contexts for electronic signature.

Both digitalni and elektronički may appear in technology-related language, but they are not always exact synonyms in formal usage.

So for this sentence, it is best to learn:

• elektronički potpis = electronic signature

as the fixed expression.

It is in the accusative singular, because it follows za in the meaning for.

However, with masculine inanimate nouns, the accusative singular is usually identical to the nominative singular.

So:

• nominative: elektronički potpis
• accusative: elektronički potpis

Same form, different grammatical role.

This is very common in Croatian, so learners often need to identify the case from the preposition and sentence structure, not just from the ending.