Learn Hardcore Croatian: Ona nikad ne nosi jaknu kad sja sunce. - She never wears a jacket when the sun shines.

Croatian uses negative concord: negative words like nikad (never), ništa (nothing), nitko (nobody) require the verb to be negated with ne. So you must say nikad ne nosi, nikad ništa ne nosi, etc. Saying nikad nosi is ungrammatical.

Do I need the subject pronoun ona?

No. Croatian is a pro‑drop language, so the subject pronoun is optional. Nikad ne nosi jaknu kad sja sunce is fully correct. Including ona adds emphasis or clarity (e.g., contrast: She, not someone else).

Why is it nosi and not ima or oblači?

nositi = to wear/carry (ongoing state): Ona nikad ne nosi jaknu = She never wears a jacket.
oblačiti/obući = to put on (the act): Nikad ne oblači jaknu = She never puts on a jacket.
imati = to have/possess: Ima jaknu = She has a jacket.

Why does jaknu end in ‑u?

jaknu is the accusative singular of the feminine noun jakna. Feminine nouns ending in ‑a typically take ‑u in the accusative singular when they’re direct objects: jakna → jaknu, haljina → haljinu, torba → torbu.

Do I need a comma before kad?

Not here. When the time clause comes after the main clause, there’s usually no comma: Ona nikad ne nosi jaknu kad sja sunce. If you place the time clause first, use a comma: Kad sja sunce, ona nikad ne nosi jaknu.

Is there any difference between kad and kada?

They mean the same. kada is a bit more formal or used to avoid awkward sound sequences; kad is shorter and very common in speech. Both are correct here.

Is sja correct? I’ve seen sija too.

In standard Croatian, “to shine” is sjati, 3rd person singular sja: sunce sja. sijati in Croatian primarily means “to sow.” In some other standards/varieties you’ll see sijati = “to shine” (sunce sija), but stick with sjati/sja for standard Croatian.

Can I say kad je sunčano instead of kad sja sunce?

Yes. Kad je sunčano (when it’s sunny) is equally natural. All of these work: kad sja sunce, kad sunce sja, kad je sunčano.

Why is it present tense? Shouldn’t it be something like “is wearing”?

Croatian present tense covers habitual actions and general truths. Ona nikad ne nosi jaknu kad sja sunce = She never wears a jacket when the sun shines/is shining (in general). For “right now,” add a time word: Sada ne nosi jaknu jer sja sunce.

Can I change the word order?

Yes, Croatian allows flexible word order for emphasis, while keeping ne immediately before the verb. Examples:

Kad sja sunce, ona nikad ne nosi jaknu.
Ona jaknu nikad ne nosi kad sja sunce.
Nikad ona ne nosi jaknu kad sja sunce. (strong emphasis on never)

Where does nikad usually go?

Adverbs of frequency typically precede the verb: (Ona) nikad ne nosi… The negation ne must come directly before the verb: nikad ne nosi (not nikad nosi).

How would I say this in the past or future?

Past habitual: Ona nikad nije nosila jaknu kad je sjalo sunce.
Future (policy/decision): Ona nikad neće nositi jaknu kad bude sunčano.
In time clauses about the future, Croatian often uses the present or Futur II: Kad bude sunčano, neće nositi…

What’s the difference between nikad and nikada?

They’re synonymous. nikada is slightly more formal or emphatic. Both are fine: Ona nikad/nikada ne nosi jaknu…

How do I say “ever” (as in “Does she ever wear…”)? Is ikad the opposite of nikad?

Use ikad mainly in questions, negatives, or conditionals:

Question: Nosi li ikad jaknu kad sja sunce? = Does she ever wear a jacket when the sun shines?
Negative: Nikad je ne nosi. = She never wears it.
Don’t use ikad in a plain positive statement; use ponekad (sometimes) instead: Ponekad nosi jaknu.

Can I use dok instead of kad?

dok = while/as long as, focusing on simultaneity. It’s fine for ongoing overlap, especially in a specific situation: Ne nosi jaknu dok sja sunce = She doesn’t wear a jacket while the sun is shining (as long as it is shining). kad is more neutral (“when/whenever”).

Is kad sja sunce the only order inside the clause? What about kad sunce sja?

Both are possible: kad sja sunce and kad sunce sja. The default neutral order is subject–verb (sunce sja), but verb–subject is also common and stylistically natural in short clauses like this.