Learn Hardcore Croatian: Njena siva jakna visi na stolici u učionici, a smeđa torba je na podu. - Her grey jacket is hanging on the chair in the classroom, and the brown bag is on the floor.

The base pronoun is ona (she).
The possessive form is njezin / njen (her).
In front of a feminine noun like jakna, you use the feminine form njezina / njena.

So:

ona → she
njezina / njena jakna → her jacket

It is feminine because jakna is a feminine noun, and adjectives/possessives must agree in gender, number, and case.

What is the difference between njena and njezina?

Both mean her and are grammatically correct.

njezina – considered a bit more standard / formal.
njena – very common in everyday speech; also used in writing.

In most contexts, you can use them interchangeably:

Njezina / Njena siva jakna visi na stolici.
Her grey jacket is hanging on the chair.

Learners can safely use njena in normal conversation and njezina if they want to sound more formal or textbook-like.

Why is it siva jakna and not jakna siva?

In Croatian, adjectives usually come before the noun:

siva jakna = grey jacket

You can say jakna je siva when you use the verb biti (to be):

Jakna je siva. = The jacket is grey.

But without je, the natural word order is:

(possessive) + adjective + noun
→ Njena siva jakna

Jakna siva by itself sounds incomplete or poetic, not normal everyday speech.

Why is the verb visi used for the jacket, but je is used for the bag?

visi = hangs / is hanging
je = is

The sentence describes the two things slightly differently:

Njena siva jakna visi na stolici…
Her grey jacket is hanging on the chair…
…a smeđa torba je na podu.
…and the brown bag is on the floor.

The jacket is described by what it’s doing (it is hanging), while the bag is described simply by where it is (on the floor).

You could also say:

Njena siva jakna je na stolici… – Her grey jacket is on the chair…
This is also correct; it just doesn’t emphasize the “hanging” action.

Why is it na stolici and u učionici? How do na and u work?

Both na and u can mean in/on/at, but they are used in different contexts:

na (on, on top of, on a surface/place)
- na stolici = on the chair
  The jacket is on the surface of the chair.
u (in, inside)
- u učionici = in the classroom
  The jacket is inside the space of the classroom.

You generally use:

na with surfaces and some locations:
na stolu (on the table), na zidu (on the wall), na stolici (on the chair)
u with enclosed spaces:
u sobi (in the room), u kući (in the house), u učionici (in the classroom)

Why do we say na stolici, u učionici, and na podu (with those endings)? What case is that?

Those words are in the locative case, used (among other things) for location after certain prepositions, especially u and na when something is at/in/on a place (not moving).

Base forms (nominative singular):

stolica (chair)
učionica (classroom)
pod (floor)

Locative singular with u / na:

na stolici – on the chair
(stolica → stolici)
u učionici – in the classroom
(učionica → učionici)
na podu – on the floor
(pod → podu)

So the pattern is:

Feminine -a nouns (stolica, učionica) → -i in locative.
Many masculine consonant-ending nouns (pod) → -u in locative.

Because the jacket and bag are not moving, we use locative with u / na to show static location.

When do we use na + locative and when na + accusative?

With na, case depends on meaning:

na + locative = location (where something is)
- Jakna visi na stolici. – The jacket is hanging on the chair.
- Torba je na podu. – The bag is on the floor.
na + accusative = direction / movement (where something is going)
- Objesila je jaknu na stolicu. – She hung the jacket on the chair.
- Stavila je torbu na pod. – She put the bag on the floor.

So:

na stolici / na podu – on the chair / on the floor (location → locative)
na stolicu / na pod – onto the chair / onto the floor (movement → accusative)

What does the conjunction a mean here, and how is it different from i?

In the sentence:

…u učionici, a smeđa torba je na podu.

a connects the two clauses and can be translated as and or but, with a slight contrast or shift of focus:

Her grey jacket is hanging on the chair in the classroom, and the brown bag is on the floor (some contrast or separation).

Differences:

i – simple and, just adding information, no contrast:
- Njena siva jakna i smeđa torba su u učionici.
  Her grey jacket and brown bag are in the classroom.
a – often and/but, marking a contrast or just “a different thing”:
- Njena siva jakna visi na stolici, a smeđa torba je na podu.
  There’s a sense of “the jacket is here, while the bag is there.”

Both are common; a is preferred when you want to separate or contrast the two parts.

Why is it smeđa torba, not smeđi torba?

Adjectives must agree with the noun’s gender, number, and case.

torba is feminine singular (nominative).
The adjective smeđ (brown) in feminine singular nominative is smeđa.

So:

masculine: smeđi kaput (brown coat)
feminine: smeđa torba (brown bag)
neuter: smeđe pismo (brown letter/envelope)

Using smeđi torba would be wrong because smeđi is a masculine form, but torba is feminine.

Why does the sentence not use any word for the or a (articles) like in English?

Croatian does not have articles like the or a/an.
Definiteness and indefiniteness are usually understood from:

context
word order
sometimes from using ovaj / taj / onaj (this / that / that over there).

In this sentence:

Njena siva jakna is naturally understood as her grey jacket (specific).
smeđa torba is the brown bag or a brown bag, depending on context.

Croatians simply say njena siva jakna and context tells you whether it’s “a” or “the” in English.

What does u učionici literally mean, and could we say na učionici?

u učionici literally: in the classroom (inside the room/space).
- u = in
- učionica → učionici (locative)

You would not normally say na učionici; that would sound like on top of the classroom (e.g., on the roof), which is not the intended meaning.

So:

u učionici – in the classroom (natural)
na učionici – on the classroom (odd, only in some very literal/physical sense)

Can we omit je in smeđa torba je na podu?

In careful, standard sentences, you normally keep je:

Smeđa torba je na podu.

In very informal or elliptical speech, people might drop it:

Smeđa torba na podu.

That shorter version sounds like a note, label, or fragment, not a full sentence. For proper, complete sentences (especially when learning), it’s better to include je.

How would word order changes affect the meaning? For example, could we say Na stolici u učionici visi njena siva jakna?

Yes, Croatian word order is flexible, and this version is also correct:

Na stolici u učionici visi njena siva jakna.

This puts more emphasis on the location first:

On the chair in the classroom hangs her grey jacket.

The original:

Njena siva jakna visi na stolici u učionici…

puts more focus on the jacket first.

Both mean the same thing; the difference is nuance and emphasis, not grammar.