Learn Hardcore Croatian: Urednik provjerava sastojke u svakom receptu za časopis. - The editor checks the ingredients in every recipe for the magazine.

A habitual action: Urednik provjerava sastojke... = The editor checks the ingredients... (this is what he usually does)
An action in progress (depending on context): The editor is checking the ingredients...

So provjerava can correspond to both checks and is checking in English, depending on context, but here it most naturally sounds like a habitual action.

Why is sastojke in that form, and which case is it?

Sastojke is the accusative plural form of sastojak (ingredient).

Nominative singular: sastojak
Accusative plural (inanimate masculine): sastojke

It’s accusative because:

provjerava is a transitive verb (to check)
The direct object (what is being checked) is sastojke (ingredients)

So: Urednik provjerava koga/što? (what?) sastojke → accusative case.

Why is it u svakom receptu and not u svaki recept or u svaki receptu?

After u, Croatian uses different cases depending on the meaning:

u + locative = in (location, inside something)
u + accusative = into (movement towards the inside)

In u svakom receptu, the meaning is in every recipe (location), so we use the locative:

svaki recept (nominative singular)
Locative singular masculine: u svakom receptu

Form details:

svaki → svakom (dative/locative masculine singular form)
recept → receptu (locative masculine singular)

So u svakom receptu literally: in every recipe (locative), not direction into every recipe.

What is the function of za časopis, and why does časopis stay in that form?

Za časopis means for the magazine.

za always takes the accusative case.
časopis is a masculine noun; nominative = časopis, accusative (singular, inanimate) is also časopis (same form, different function).

So:

Nominative: časopis (subject)
Accusative: časopis (object after za)

Here za časopis expresses purpose or target: the editor checks the ingredients for the magazine (i.e., for publication in that magazine).

Why is urednik in this form, and how do we know it’s the subject?

Urednik is the nominative singular form of urednik (editor).

Nominative is the case used for the subject of the sentence.
The basic word order in Croatian, like English, is often Subject–Verb–Object.

In Urednik provjerava sastojke...:

urednik (nominative) = subject
provjerava = verb
sastojke (accusative) = direct object

The combination of nominative case and initial position makes it clear that urednik is the one performing the action.

Could the word order be changed? For example, can I say Sastojke urednik provjerava u svakom receptu za časopis?

Yes. Croatian has relatively flexible word order, and all of these are grammatically possible:

Urednik provjerava sastojke u svakom receptu za časopis.
Sastojke urednik provjerava u svakom receptu za časopis.
U svakom receptu urednik provjerava sastojke za časopis.

The case endings tell you who does what, so meaning stays basically the same. What changes is emphasis:

Starting with Urednik: neutral, focus on the editor.
Starting with Sastojke: emphasis on the ingredients (that’s what he is checking).
Starting with U svakom receptu: emphasis on every recipe (how thoroughly he checks).

For a learner, the original order (subject–verb–object) is the safest and most neutral.

What is the difference between provjerava sastojke u svakom receptu and provjerava sastojke svakog recepta?

Both can translate as checks the ingredients of every recipe, but there is a nuance:

u svakom receptu = literally in every recipe, locative
- More concrete, visual: he looks inside each recipe and checks its ingredients.
svakog recepta = genitive of every recipe
- More abstract, possessive: the ingredients of each recipe.

So:

Urednik provjerava sastojke u svakom receptu.
Urednik provjerava sastojke svakog recepta.

Both are correct; the first sounds a bit more natural and direct in everyday speech.

How would the sentence change if the editor were female?

Only urednik would change; the verb and the rest stay the same in the present tense.

Common options:

Urednica provjerava sastojke u svakom receptu za časopis.
- urednica is the feminine noun for female editor.

In the present, the verb provjerava does not change for gender. Gender differences show up more clearly in the past tense:

Muško: Urednik je provjeravao sastojke...
Žensko: Urednica je provjeravala sastojke...

Why isn’t there a word for the in Urednik provjerava...? How do we know it’s the editor and not an editor?

Croatian has no articles (no the, a, an), so urednik can mean:

an editor
the editor

The exact meaning depends on context, not on a separate word.

In many real situations, if the participants already know which editor is being discussed, urednik is understood as the editor. If it’s the first time we mention him, it might be more natural to translate it as an editor.

So:

Urednik provjerava sastojke... could be:
- The editor checks the ingredients...
- An editor checks the ingredients...

English articles are chosen when translating, but they are not present in the Croatian sentence.

Could I replace provjerava with another verb like pregledava or kontrolira? Would the meaning change?

Yes, you can, with slight nuances in meaning:

provjerava – checks, verifies; most neutral for checking correctness.
pregledava – goes through, reviews; suggests going over the recipes/ingredients, possibly more general.
kontrolira – controls, inspects; sounds a bit more formal or strict, like quality control.

Examples:

Urednik provjerava sastojke u svakom receptu za časopis.
→ He checks/verifies ingredients (are they correct, complete, etc.).
Urednik pregledava sastojke u svakom receptu za časopis.
→ He goes through/reviews the ingredients (reads them over).
Urednik kontrolira sastojke u svakom receptu za časopis.
→ He controls/inspects the ingredients (quality control, standards).

All are grammatically fine; provjerava is the most typical in this context.