Learn Hardcore Croatian: Njena kćer je hrabra kada govori hrvatski pred razredom. - Her daughter is brave when she speaks Croatian in front of the class.

Njena is the short, very common spoken form.
Njezina is the full feminine form (also very common, especially in writing).
Njezin is the masculine/neuter form.

The word kćer (daughter) is grammatically feminine, so the possessive has to be feminine too:

njena kćer = her daughter
njezina kćer = her daughter (a bit more formal / full form)

Njezin kćer is wrong, because njezin is masculine/neuter, and it doesn’t agree in gender with kćer.

Is kćer feminine or masculine? How does that affect hrabra?

Kćer (also kći) is grammatically feminine, even though it does not end in -a like many feminine nouns.

Because it is feminine, any adjective that describes it must also be feminine:

kćer je hrabra = the daughter is brave (feminine)
If it were masculine, you would say hrabar:
- sin je hrabar = the son is brave

So hrabra is in the feminine singular nominative form, agreeing with kćer.

Why do we need je in Njena kćer je hrabra? Can we leave it out?

Je is the 3rd person singular form of the verb biti (to be), meaning is.

Njena kćer je hrabra = Her daughter is brave.

In standard Croatian, you cannot normally leave it out in the present tense. Without je, the sentence is incomplete or sounds like a headline or a very telegraphic style:

Njena kćer hrabra – sounds like a note or a label, not a normal full sentence.

So: in normal spoken and written Croatian, you need je here.

Can the position of je change, for example Njena kćer hrabra je kada…?

The verb je is a clitic and Croatian has quite strict rules about clitic placement:

It usually goes in second position in the clause, after the first stressed word or phrase.

Natural positions here are:

Njena kćer je hrabra kada govori…
Njena je kćer hrabra kada govori… (a bit different emphasis: HER daughter is brave…)

Something like:

Njena kćer hrabra je kada govori…

sounds unnatural or wrong, because je is pushed too far to the right. So you generally keep je near the beginning, in that “second position” slot.

What is the difference between kada and kad in kada govori hrvatski?

Kada and kad both mean when.

Kad is the shorter, very common everyday form.
Kada is a bit more formal or careful, but also completely normal in speech.

You can use either here:

…kada govori hrvatski pred razredom.
…kad govori hrvatski pred razredom.

They don’t change the meaning; it’s mostly style/length.

Why is govori in the present tense? Does it mean she is speaking right now or that she usually does this?

In Croatian, the present tense can express:

An action happening right now
- Sada govori hrvatski. = She is speaking Croatian now.
A general or habitual situation / characteristic
- Hrabra je kada govori hrvatski pred razredom.
  = She is (always / generally) brave when she speaks Croatian in front of the class.

Here, because we’re talking about her courage as a general trait, govori is understood as habitual: whenever this situation happens, she shows bravery.

Why is it just govori hrvatski and not govori hrvatski jezik?

In Croatian, you very often use just the adjective form of the language name as the object of govoriti:

govoriti hrvatski = to speak Croatian
govoriti engleski = to speak English
govoriti njemački = to speak German

The full forms hrvatski jezik, engleski jezik are also correct, but they sound more formal, and in everyday speech people almost always drop jezik.

So:

govori hrvatski = she speaks Croatian (language)
No extra noun is needed.

Why does hrvatski end in -i here? Isn’t that masculine nominative?

Yes, hrvatski is the masculine singular nominative form of the adjective hrvatski (Croatian).

When you say govoriti + language, Croatian uses this adjective form as the direct object, but in practice it behaves almost like an adverb:

govoriti hrvatski = to speak Croatian
čitati hrvatski (rare, but possible) = to read (in) Croatian

Grammatically, you can think of it as a short form standing in for “hrvatski jezik” (Croatian language), but in actual usage, govoriti hrvatski is a fixed and very natural pattern.

What does pred razredom literally mean, and why is it razredom and not razred?

Pred razredom literally means in front of the class.

pred is a preposition meaning in front of / before.
With a static location (“in front of somewhere” – not movement), pred takes the instrumental case.

So:

razred (nominative) = class
razredom (instrumental) = (in front of) the class

That’s why you see razredom: it’s instrumental singular, required by pred when expressing location.

Which case is razredom, and how is it formed?

Razredom is instrumental singular.

For a masculine noun like razred:

Nominative (basic form): razred – a class
Instrumental singular: razredom – (with / by / in front of) the class

The instrumental ending for many masculine nouns is -om:

grad → gradom (city → with the city / through the city)
razred → razredom
stol → stolom

Could I say Njena kćer je hrabra kada govori pred razredom hrvatski instead?

You could move hrvatski to the end, and the sentence would still be understandable, but it sounds odd and unnatural.

The usual and most natural order is:

govori hrvatski pred razredom

because govori hrvatski (speaks Croatian) is a tight verb–object pair, and pred razredom is a location phrase that normally comes after that.

Putting hrvatski at the very end (pred razredom hrvatski) can sound like you’re awkwardly emphasizing Croatian in a way that native speakers don’t usually do here.

Are kćer, kći, and kćerka all the same word? Which one should I use?

All three refer to a daughter, but usage differs slightly:

kćer – very common, standard, used a lot in both speech and writing.
kći – also standard, but sounds a bit more formal / literary to some speakers.
kćerka – more colloquial/regional; common in some areas and in neighboring countries.

As a learner, kćer is a safe and very natural standard choice:

Njena kćer je hrabra… – perfectly normal Croatian.

How do you pronounce kćer, and what is the difference between ć and č?

Kćer is pronounced roughly like:

k-ćer in one smooth cluster; you don’t fully release k before ć.
IPA: [ktɕeːr] or [kɕeːr], depending on speaker.

About the letters:

ć is a softer sound, similar to the t in British “tune” (with y-sound: “tyune”), or something between t and ch.
č is harder, like ch in chair.

Minimal example:

čaj – tea (hard č)
ćaj – would sound wrong / dialectal; standard language uses čaj.

So in kćer, the ć is that softer palatal sound, not the strong ch of English.