Learn Hardcore Croatian: Roditelji ponosno gledaju sina i kćer. - The parents proudly watch their son and daughter.

Croatian has no articles (“the” or “a/an”) at all.
Whether you translate it as “the parents proudly watch the son and daughter” or “(some) parents proudly watch their son and daughter” depends entirely on context.

Roditelji = parents (can be the parents or just parents in general)
sina = son (can be the son or their son)
kćer = daughter (can be the daughter or their daughter)

Croatian leaves definiteness and possession to be inferred from the situation, not from little words like “the.”

Why is “roditelji” used instead of a singular form? How do you say “a parent” in Croatian?

Roditelji is the plural form and means “parents”.

roditelj = a parent (singular)
roditelji = parents (plural)

In your sentence:

Roditelji ponosno gledaju… = The parents proudly watch…

If you wanted “The father proudly watches the son and daughter”, you would say:

Otac ponosno gleda sina i kćer.

If you wanted “The mother proudly watches the son and daughter”:

Majka ponosno gleda sina i kćer.

Why is the verb “gledaju” and not “gleda”?

The verb must agree with the subject in person and number.

The verb is gledati = to watch / to look at.
gledaju is 3rd person plural, present tense → they watch.
Roditelji = parents → plural → they.

So:

Roditelji gledaju… = The parents watch…
Roditelj gleda… = The parent watches… (singular)

Forms of gledati in the present tense:

ja gledam – I watch
ti gledaš – you (sg) watch
on/ona/ono gleda – he/she/it watches
mi gledamo – we watch
vi gledate – you (pl/formal) watch
oni/one/ona gledaju – they watch

Your sentence uses the oni/one/ona form: gledaju.

Why is it “sina” and not “sin”?

Sin means “son” in the nominative case (the “dictionary form”).
In the sentence, “son” is the direct object of the verb gledaju, so it takes the accusative case.

For a masculine animate noun like sin:

Nominative (subject): sin – The son is happy. → Sin je sretan.
Accusative (direct object): sina – They watch the son. → Gledaju sina.

In your sentence:

gledaju sina = they watch (their) son
So sina is the accusative singular of sin.

Why does “kćer” stay the same and not become something like “kćeru”?

Feminine nouns in Croatian don’t all behave the same way. Some end in -a in the nominative (like žena → ženu), and some do not end in -a, like kćer.

Kćer (daughter) has:

Nominative singular: kćer – The daughter is here. → Kćer je ovdje.
Accusative singular: kćer – They watch the daughter. → Gledaju kćer.

So nominative and accusative look the same for this noun.

You will also see variants:

kći (another standard form)
kćerka (colloquial/common in many regions)

With kćerka, the accusative changes:

Nominative: kćerka
Accusative: kćerku → Gledaju kćerku.

But with kćer, the form in your sentence, nominative and accusative are identical.

Why is there no word for “their” in “gledaju sina i kćer”?

Croatian often omits possessive pronouns like “my, your, his, her, their” when the owner is obvious from context.

Here, the subject is the parents, and the objects are son and daughter, so it’s naturally understood to mean “their son and (their) daughter.”

If you really want to make possession explicit, you could say:

Roditelji ponosno gledaju svog sina i svoju kćer.
(The parents proudly watch their son and their daughter.)

But the basic sentence without possessives is completely natural and usually preferred.

What is the function of “ponosno”, and where can it go in the sentence?

Ponosno is an adverb meaning “proudly.” It describes how the parents are watching.

In Croatian, adverbs are quite flexible in position. All of these are possible:

Roditelji ponosno gledaju sina i kćer. (neutral, very natural)
Roditelji gledaju sina i kćer ponosno. (slight emphasis on proudly, often more emotional or stylistic)
Ponosno roditelji gledaju sina i kćer. (strong emphasis on proudly)

The most neutral, everyday version is the one you have:
Subject – adverb – verb – object.

What does “i” mean and how is it used here?

I is the basic coordinating conjunction meaning “and.”

In your sentence:

sina i kćer = son and daughter

It simply links two objects of the same verb:

gledaju sina i kćer = they watch the son and (they watch the) daughter.

You don’t have to repeat the preposition or case marking; i shares them:

gledaju sina i kćer (both in the accusative as direct objects of gledaju).

How do you pronounce “roditelji” and what is that “lj”?

Roditelji is pronounced approximately like: roh-dee-te-lyi (all short, clean vowels).

The “lj” represents a single sound, like the “lli” in “million” in many English accents. It’s a palatalized L.

Syllables:

ro – di – te – lji

Don’t split lj into two separate consonants; think of it as one sound: /ʎ/.

What is the difference between “ć” and “č” in Croatian, as in “kćer”?

Both ć and č are “ch-like” sounds, but they are different phonemes:

č is a harder, more emphatic sound, like “ch” in “church.”
ć is softer, more palatal, somewhat like a very soft “t” + “y” combo.

In kćer, the ć is part of a consonant cluster kć:

kćer ≈ k-tyer (but said very quickly, as one cluster)

The distinction is important in spelling and can change meaning (though English speakers often need time to reliably hear and produce it).

Why does the verb “gledaju” not take a preposition like “at”, as in “look at”?

Croatian gledati already means “to look at / to watch.”
You don’t add a preposition like “at” the way you do in English.

So:

gledati televiziju = to watch TV
gledati (nekoga) = to watch / look at (someone)

Your sentence:

gledaju sina i kćer = they watch / they are looking at (their) son and daughter.

Sometimes you will hear gledati u + accusative for “to look into / to stare at”, with a bit more focus on the direction of the gaze:

Gledaju u sina. = They are looking at (staring at) the son.

But the basic gledaju sina already covers “watch / look at the son.”

Could this sentence mean they are proud of their children, or just that they are watching them proudly?

Literally, “Roditelji ponosno gledaju sina i kćer” means:

“The parents proudly watch (their) son and daughter.”

It emphasizes the manner of watching (they are proud as they look at them).
In context, this almost always implies they are proud of them, which is why they are watching them with pride.

However, if you wanted to express “They are proud of their son and daughter” without the idea of looking, you would typically say:

Roditelji su ponosni na sina i kćer.
(The parents are proud of their son and daughter.)

So:

ponosno gledaju = proudly watch (action + manner)
su ponosni na = are proud of (state/feeling)