Learn Hardcore Croatian: Kad god se brineš, nazovi me i zajedno ćemo naći rješenje. - Whenever you worry, call me and we will find a solution together.

Kad se brineš, nazovi me.
→ When you are worried, call me. (could sound like a specific situation, or more one‑off)
Kad god se brineš, nazovi me.
→ Whenever you are worried, call me (any time). (clearly general, repeated offer)

In practice, kad god emphasizes “every time / no matter when,” which fits the emotional support tone of the sentence very well.

Is there any difference between kad god and kada god?

Semantically, no — they mean the same thing: whenever.

kad god is simply a shorter, more colloquial form.
kada god is slightly more formal or careful speech/writing, but still very common.

You can say:

Kad god se brineš, nazovi me…
Kada god se brineš, nazovi me…

Both are correct; the choice is mostly style and rhythm.

Why is it se brineš and not just brineš? What does se do here?

Brinuti se is a reflexive verb in Croatian meaning to worry, to be concerned.

brinuti (without se) usually means to take care (of), to look after someone/something.
brinuti se (with se) means to worry.

Examples:

Brinem se za tebe. – I worry about you.
Brinem o djeci. – I take care of the children. (no se)

In your sentence:

Kad god se brineš…
→ Whenever you are worried…

Without se, Kad god brineš… would sound wrong in this meaning; it would suggest “whenever you care / look after [something]” but with no object, so it’s ungrammatical or at least very odd.

Is there a difference between brineš se and zabrinut si?

Both refer to being worried, but they’re used a bit differently:

brineš se = you are worrying / you worry
– Focuses on the ongoing mental activity; often used with za / oko:
- Brineš se previše. – You worry too much.
- Brineš se za ispit. – You’re worried about the exam.
zabrinut si = you are worried / you are concerned (adjective)
– Focuses on your emotional state:
- Vidim da si zabrinut. – I see that you’re worried.

In Kad god se brineš…, the idea is “every time you are in that worrying state / whenever you find yourself worrying,” so brineš se is natural.

Why is brineš in the present tense if we’re talking about future situations?

Croatian (like many other languages) often uses the present tense in time clauses introduced by kad / kada / kad god when referring to the future.

So:

Kad god se brineš, nazovi me…
literally: Whenever you worry, call me…
meaning: Whenever you *will be worried (in the future), call me…*

If you used the future here:

Kad god ćeš se brinuti, nazovi me…

it would sound unnatural or wrong.
The rule of thumb: after kad / kada / kad god (and similar time words), Croatian typically uses present tense to refer to future events.

What form is nazovi? Why not zovi?

Nazovi is the imperative (command form) of nazvati = to call (by phone).

nazvati → nazovi (ti) – call (me)
zvati means to call in a more general sense (to call someone’s name, to be named, or also “to call by phone” in colloquial speech), with imperative:
- zovi (ti) – call

In this context:

Nazovi me = Call me (on the phone).
Zovi me can also mean “Call me” (more colloquial, can include phone), but nazovi me is clearer and slightly more standard when you specifically mean making a phone call.

Why is it nazovi me, and not nazovi mene? Is me always necessary?

me is the unstressed (clitic) form of mene (“me”).

Nazovi me. – completely normal and neutral: Call me.
Nazovi mene. – also correct, but emphasizes me (“call me (not someone else)”).

You almost always use me in neutral sentences; mene appears when you need emphasis or contrast.

You can’t omit the object here; nazovi without anything usually feels incomplete in this context. You need to say nazovi me (call me) or nazovi me kad god se brineš etc.

Why is it zajedno ćemo naći rješenje and not zajedno naći ćemo rješenje?

In Croatian future tense (with ću, ćeš, će, ćemo, ćete, će), the auxiliary usually comes before the main verb in neutral word order:

Mi ćemo naći rješenje. – We will find a solution.

When you add another word like zajedno (together), it often goes before the auxiliary:

Zajedno ćemo naći rješenje. – Together we will find a solution.

Zajedno naći ćemo rješenje is grammatically possible but sounds unnatural and marked; native speakers almost never say it like that. The standard, natural order is:

Zajedno ćemo naći rješenje.

Could we say naći ćemo rješenje instead of ćemo naći rješenje?

Yes, both are possible, but they differ in style and frequency:

Ćemo naći rješenje.
(as in zajedno ćemo naći rješenje)
– Auxiliary ćemo before the main verb: this is the most common and neutral order in modern standard Croatian.
Naći ćemo rješenje.
– Main verb before ćemo: this order also exists and is correct, but it’s less common, can sound slightly more emphatic or stylistically marked, and is often found in more formal or literary contexts.

In your sentence, zajedno ćemo naći rješenje is the most natural everyday version.

Why is there a comma after brineš: Kad god se brineš, nazovi me…?

Croatian punctuation requires a comma between a dependent clause and the main clause, and kad god se brineš is a dependent (time) clause.

Structure:

Dependent clause: Kad god se brineš – Whenever you’re worried
Main clause: nazovi me i zajedno ćemo naći rješenje – call me and we’ll find a solution together

When the dependent clause comes first, you must separate it from the main clause with a comma:

Kad god se brineš, nazovi me…
Kad dođeš, javi mi se. – When you come, let me know.

If the main clause came first, you’d still usually write a comma:

Nazovi me kad god se brineš.

Is this sentence formal or informal? How would I say it politely to someone I don’t know well or to more than one person?

The sentence is informal singular, addressed to one person you’re close to, because it uses:

brineš (2nd person singular)
nazovi (2nd person singular imperative)

For a polite / plural version (to one person formally or to a group), you’d use vi‑forms:

Kad god se brinete, nazovite me i zajedno ćemo naći rješenje.

Differences:

brineš → brinete
nazovi → nazovite

Everything else stays the same.

Why is it spelled rješenje and not riješenje?

The standard spelling is rješenje (one e), meaning solution.

In Croatian, the sequence rje is written as such, not rije, in many words:

rješenje (solution)
vrijeme (time, weather) – different word, but similar pattern: vrijeme, not vrjeme
prijedlog (proposal; preposition), etc.

Learners often over-insert i (riješenje), but that’s non-standard. So:

Correct: rješenje
Incorrect: riješenje

Pronunciation is close to rje‑ as one unit; the spelling follows that pattern.