Learn Hardcore Croatian: U jutarnjim novinama novinar objavljuje članak s drugim naslovom. - In the morning newspaper the journalist publishes an article with a different title.

Locative when it means in/inside (static location):
- u jutarnjim novinama = in the morning newspaper(s)
Accusative when it means into/to (movement):
- u jutarnje novine = into the morning newspapers (movement, like “put it into the morning papers”)

Here we are talking about where the article appears (static location), so locative (u jutarnjim novinama) is correct.

Why does jutarnjim end in -im?

Because jutarnjim agrees in gender, number, and case with novinama:

Noun: novine (feminine, plural)
Case here: locative plural
Adjective: jutarnji → locative plural feminine = jutarnjim

Regular pattern (feminine plural adjective endings):

Nominative: jutarnje novine
Genitive/Dative/Locative/Instrumental: jutarnjih / jutarnjim / jutarnjim / jutarnjim novinama
(there are some syncretic forms, but the point is: locative plural feminine often has -im for adjectives)

What exactly is the role of u here? How do I know it takes locative and not accusative?

u can mean either:

in / inside → static location → locative
- u školi (in school)
- u gradu (in the city)
- u jutarnjim novinama (in the morning newspaper(s))
into / to → movement → accusative
- ići u školu (to go to school)
- ući u grad (to enter the city)
- staviti oglas u novine (to put an ad into the newspaper)

In your sentence, nothing is moving into the newspapers; we’re simply saying where the article appears. So u = in, and that requires locative.

Why is it novinama and not just novine?

Novine is the nominative plural form (the dictionary form).
With the preposition u + “in” meaning, we must use the locative:

Nominative plural: novine (These are the newspapers.)
Locative plural: novinama (in the newspapers)

So:

Novine su skupe. – The newspapers are expensive. (nominative)
Čitam u novinama. – I am reading in the newspapers. (locative)

Your sentence uses the second situation (location), so novinama.

Could I say U jutarnjim novinama se objavljuje članak instead of novinar objavljuje članak?

Yes, but the meaning changes slightly.

Novinar objavljuje članak – literally The journalist publishes an article.
Focus on the agent (the journalist).
U jutarnjim novinama se objavljuje članak – An article is being published in the morning newspapers.
This is a reflexive/passive-like construction; it doesn’t mention who publishes it. Focus is on the event or the article itself, not on the journalist.

Both are grammatically fine, but they answer slightly different questions:

Who publishes it? → Novinar objavljuje članak.
What is happening in the newspapers? → U jutarnjim novinama se objavljuje članak.

What aspect and tense is objavljuje? Does it mean “is publishing” or “publishes”?

Objavljuje is:

Present tense
Of the imperfective verb objavljivati (to publish, be publishing)

Depending on context, Croatian present imperfective can correspond to both English:

Present continuous:
- Novinar objavljuje članak. – The journalist is publishing an article (right now).
Present simple (habitual/repeated):
- Novinar svakog jutra objavljuje članak. – The journalist publishes an article every morning.

So objavljuje is flexible: is publishing or publishes, depending on context.

Why is it s drugim naslovom and not s drugi naslov?

Because s (with) requires instrumental case when it means “with (something/someone)”:

Noun: naslov (title, masculine singular)
Instrumental singular: naslovom
Adjective: drugi (other/second) → instrumental singular masculine: drugim

So:

s drugim naslovom = “with another title / with a different title”

Compare:

Nominative: drugi naslov je čudan – The other title is strange.
Instrumental: članak s drugim naslovom – an article with another title.

Why is the preposition s used and not sa in s drugim naslovom?

Both s and sa mean with. The difference is mostly phonetic (for easier pronunciation):

Use s before most consonants and vowels.
Use sa:
- before words starting with s, z, š, ž to avoid tongue-twisters
- or before some consonant clusters for easier pronunciation.

Examples:

s bratom (with my brother) – fine with s
sa sestrom (with my sister) – easier than s sestrom
sa školom (with the school) – easier than s školom

s drugim naslovom is easy to pronounce, so s is natural here.
sa drugim naslovom is not wrong, but sounds heavier and is less common in this exact phrase.

Why is drugim ending in -im here?

Because drugim is:

Masculine
Singular
Instrumental case (agreeing with naslovom)

Declension (masculine singular, hard-stem adjective like drugi):

Nominative: drugi naslov
Genitive: drugog naslova
Dative/Locative: drugom naslovu
Accusative: drugi naslov (for animate objects: drugog, but naslov is inanimate)
Instrumental: drugim naslovom

So the -im ending marks the instrumental adjective form.

Could I say članak s drugim naslovom u jutarnjim novinama instead? Is that still correct?

Yes, that order is still grammatical:

Novinar objavljuje članak s drugim naslovom u jutarnjim novinama.

Croatian word order is fairly flexible. The basic meanings stay the same, but the focus can shift a little depending on what comes at the beginning or the end.

Some possible orders:

U jutarnjim novinama novinar objavljuje članak s drugim naslovom.
→ Strong focus on in the morning newspapers (as the context/scene).
Novinar u jutarnjim novinama objavljuje članak s drugim naslovom.
→ Focus on the journalist and where he publishes.
Novinar objavljuje članak s drugim naslovom u jutarnjim novinama.
→ Slight focus on what kind of article (with another title) and where.

All are correct; you choose based on what you want to emphasize.

Is there any difference between novinar objavljuje članak and objavljuje članak novinar?

Both are grammatically correct, but they sound different in terms of emphasis:

Novinar objavljuje članak.
Neutral statement, typical word order: subject – verb – object.
Objavljuje članak novinar.
Less common, sounds more marked or stylistic, and can emphasize that it is specifically the journalist (and not someone else) who publishes it. This kind of inversion might show up in literary style, headlines, or for contrast.

In everyday speech, the normal choice is Novinar objavljuje članak.