Njena adresa je u mojoj ulici, blizu škole.

Because after the preposition u meaning in, Serbian normally uses the locative case for location.

• moja ulica = my street in the dictionary/basic form
• u mojoj ulici = in my street / on my street

Both words change because the noun phrase has to agree in case:

• moja → mojoj
• ulica → ulici

So u mojoj ulici is the correct locative form.

Ulica is a feminine noun, and in the locative singular it changes to ulici.

This is a very common pattern for feminine nouns ending in -a:

• škola → u školi
• soba → u sobi
• ulica → u ulici

Since the sentence is talking about location, u requires the locative here, so ulica becomes ulici.

Because blizu is followed by the genitive case, not the locative.

So:

• škola = basic form
• škole = genitive singular

That is why you say:

• blizu škole = near the school

This is important because different Serbian prepositions and adverbs require different cases:

• u školi = in the school → locative
• blizu škole = near the school → genitive

Njena means her. It is a possessive adjective.

It agrees with the noun it describes:

• njena adresa = her address
• njena škola = her school
• njeno ime = her name

Here it is njena because adresa is feminine singular.

You may also encounter njezina, which means the same thing and is more common in some regional varieties. In standard Serbian, njena is very common.

The comma separates an added location phrase.

The sentence has:

• Njena adresa je u mojoj ulici = main statement
• blizu škole = extra information уточifying where in the street

In English, this is a bit like saying:

• Her address is on my street, near the school.

The comma is natural here because blizu škole is an additional descriptive phrase. You may also sometimes see similar sentences without a comma in informal writing, but with the comma it is clear and natural.

Adresa literally means address, but in everyday use it can also refer to someone’s place/location in the sense of where they live.

So in this sentence, Njena adresa je u mojoj ulici naturally means that her home address is on your street.

Depending on context, adresa can also mean:

• a mailing/street address
• a web address
• an official address/location

But in this sentence, the physical street location is clearly meant.

Serbian has a strong tendency for short unstressed words, called clitics, to appear in the second position of the clause. The verb je is one of them.

So:

• Njena adresa je u mojoj ulici.

Here je comes after the first phrase Njena adresa.

This is very normal in Serbian word order. You will often see things like:

• Ona je ovde.
• Moj brat je kod kuće.
• Njena adresa je u mojoj ulici.

Even though Serbian word order is flexible, clitics like je have special placement rules.

In this sentence, u mojoj ulici is the more natural choice.

Why? Because Serbian usually treats a street as a kind of area/location you are in:

• živim u ovoj ulici
• u mojoj ulici ima mnogo drveća

However, learners may notice that in some contexts Serbian can use na with places, especially with things like squares, roads, islands, events, and surfaces. But for ulica, when talking about an address being located there, u mojoj ulici is the standard and safest choice.

Serbian has no articles like a or the.

So škola or škole can mean:

• a school
• the school

The exact meaning comes from context.

In blizu škole, the listener will usually understand near the school because both speaker and listener probably know which school is meant, or because it is the obvious nearby school in that area.

This is completely normal in Serbian.

Yes. A very literal translation would be in my street, because Serbian uses u.

But in natural English, we usually say on my street.

So:

• Serbian: u mojoj ulici
• natural English: on my street

This is a good example of how prepositions do not always match word-for-word between languages.

In practice, it describes the location of the address more specifically.

The main idea is:

• Her address is on my street

Then blizu škole adds:

• near the school

So it functions as an additional location phrase, not as something grammatically attached only to ulici. It tells you where her address is, more precisely.

You can think of the structure like this:

• Njena adresa je = Her address is
• u mojoj ulici = on my street
• blizu škole = near the school

Together: Her address is on my street, near the school.