Learn Hardcore Croatian: U obitelji uglavnom razgovaramo ozbiljno, ali ponekad volimo dobru šalu i opušten dogovor. - In the family we mostly talk seriously, but sometimes we like a good joke and a relaxed agreement.

Literally, u obitelji means “in (the) family”.
Here u + locative (obitelji) expresses the setting / environment in which something happens, so the idea is “within our family (circle) we mostly talk seriously.”

You could say s obitelji (“with (my) family”), but that usually appears with verbs like biti s obitelji (to be with family), provoditi vrijeme s obitelji (spend time with family). With razgovarati, u obitelji feels more like describing the general atmosphere or norm inside the family, which fits this sentence well.

Why is it obitelji and not obitelj? What case is this?

The base noun is obitelj (family), which is feminine.
After the preposition u in the sense of location (“in/within”), Croatian uses the locative case.

The locative singular of obitelj is obitelji, so:

nominative: obitelj (family)
locative: u obitelji (in the family)

What does uglavnom mean exactly, and where can it go in the sentence?

Uglavnom means “mostly, mainly, generally, for the most part.”

It’s an adverb and is quite flexible in position. All of these are possible and natural:

U obitelji uglavnom razgovaramo ozbiljno.
U obitelji razgovaramo uglavnom ozbiljno.
Uglavnom u obitelji razgovaramo ozbiljno. (more emphasis on in the family)

The original word order is the most neutral and natural for stating a general habit.

What’s the nuance of razgovaramo compared to pričamo? Could we say pričamo ozbiljno?

Both razgovarati and pričati can mean “to talk”, but:

razgovarati suggests a conversation / discussion (more mutual, structured).
pričati can mean “to talk, to chat, to tell (a story)”, often more informal or one-sided.

You can say pričamo ozbiljno, and people would understand it. But razgovaramo ozbiljno fits better when you want to emphasize serious conversations or discussions within the family.

Why is ozbiljno used here and not ozbiljan?

Ozbiljan is the adjective “serious” (masculine form), used to describe a noun:

ozbiljan razgovor – a serious conversation

Ozbiljno is the adverb “seriously,” used to describe how the talking happens:

razgovaramo ozbiljno – we talk seriously

Because it’s modifying the verb razgovaramo, the adverb form ozbiljno is correct.

Why is the present tense razgovaramo / volimo used? Does it mean “right now” or “in general”?

In Croatian, the simple present tense is used both for current actions and for habits / general truths, just like the English “we talk” / “we usually talk”.

Here, because we have uglavnom (mostly) and ponekad (sometimes), it clearly refers to a habitual pattern:
> We usually talk seriously, but sometimes we like a good joke…

What does ponekad mean, and can it move around in the sentence?

Ponekad means “sometimes”.

It can be placed in different positions with similar meaning:

… ali ponekad volimo dobru šalu… (neutral)
… ali volimo ponekad dobru šalu… (slightly different rhythm)
… ali volimo dobru šalu ponekad… (adds a bit of end-focus on sometimes)

The original placement, after ali, is the most typical and natural.

Why is it volimo dobru šalu and not something like volimo dobra šala?

The base noun is šala (joke), which is feminine singular.
After voljeti (“to like, to love”), the object is in the accusative case.

So we need feminine singular accusative:

nominative: dobra šala
accusative: dobru šalu

That’s why the sentence has volimo dobru šalu – both the adjective (dobru) and the noun (šalu) are in the accusative.

What is the exact meaning of dogovor here? Is it like “agreement”, “plan”, “deal”, or “chat”?

The noun dogovor literally means “agreement, arrangement, something we have agreed on.”
It can be understood as:

a plan / arrangement we have with each other
an agreement (formal or informal)

In this sentence, opušten dogovor suggests something like a relaxed, informal arrangement or plan, as opposed to something strict or serious. It’s not “chat”; a “chat” would more likely be razgovor.

What does opušten mean, and what form is it in here?

Opušten means “relaxed, laid‑back, easy‑going.”

Here it’s the adjective modifying dogovor (a masculine singular noun) in the accusative singular masculine:

nominative: opušten dogovor (a relaxed agreement)
accusative: opušten dogovor (same form for masculine inanimate nouns)

So volimo … opušten dogovor = “we like a relaxed arrangement.”

Why is there a comma before ali, and is that always required?

Yes, in standard Croatian you always put a comma before ali when it joins two clauses, just like “but” in English when it connects full clauses:

…razgovaramo ozbiljno, ali ponekad volimo dobru šalu…

This comma marks a contrast between two statements:

we mostly talk seriously
but sometimes we like a good joke and a relaxed arrangement.

Can I say U obitelji razgovaramo uglavnom ozbiljno, ali volimo ponekad dobru šalu i opušten dogovor instead? Does it sound natural?

Yes, that is still grammatically correct and understandable, but the rhythm and emphasis change slightly.

The original — U obitelji uglavnom razgovaramo ozbiljno, ali ponekad volimo… — sounds more natural and fluent. Native speakers tend to place uglavnom and ponekad early in their respective clauses, as in the original sentence.