Roditelji se javljaju čim stignu na odredište, da se ne brinemo.

In this sentence, both javljati se and brinuti se are verbs that normally appear with se.

• javljati se = to get in touch, to call, to check in, to report back
• brinuti se = to worry

So se here is not a separate word meaning oneself in the usual English sense. It is part of the verb expression.

Compare:

• javljaju on its own would not mean the same thing as javljaju se
• brinemo on its own is not the normal form for we worry; the usual verb is brinemo se

This is something English speakers often just need to learn verb by verb.

Javljati se is a very common Croatian verb with a broad meaning. Depending on context, it can mean:

• to call
• to contact someone
• to check in
• to let someone know
• to report back

In this sentence, it most likely means something like:

• they’ll get in touch
• they’ll let us know
• they’ll check in

So it is more general than just to telephone.

Croatian often uses the present tense where English would use the future, especially when talking about:

• arranged or expected future actions
• repeated actions
• actions linked to time clauses such as when, as soon as, etc.

So Roditelji se javljaju čim stignu... can sound natural even if English would prefer will call / will get in touch.

Depending on context, this sentence may mean either:

• a habitual action: The parents get in touch as soon as they arrive...
• a future/expected action: The parents will get in touch as soon as they arrive...

Croatian allows this kind of present-tense usage much more freely than English.

After čim (as soon as), Croatian normally uses the present tense, not the future tense.

So:

• čim stignu = as soon as they arrive

This is very normal Croatian structure. English also avoids the future after as soon as:

• English: as soon as they arrive, not usually as soon as they will arrive
• Croatian: čim stignu, not čim će stići

So this part is actually quite parallel to English.

This is about aspect, which is very important in Croatian.

• stići is perfective
• stizati is imperfective

Here we get stignu, which is the present form of the perfective verb stići.

Why perfective? Because the sentence refers to a completed event:

• they arrive
• and once that arrival is completed, they contact us

So čim stignu means as soon as they have arrived / as soon as they arrive.

If you used stižu, it would suggest an ongoing or repeated process of arriving, which does not fit as well here.

This is another aspect pair:

• javljati se = imperfective
• javiti se = perfective

Very roughly:

• javljati se focuses on the action as ongoing, repeated, habitual, or simply viewed without emphasis on completion
• javiti se focuses on one completed act of getting in touch

So:

• Roditelji se javljaju... can sound habitual or generally expected
• Roditelji će se javiti... would more clearly sound like one future completed contact

Both can be natural in the right context, but they are not exactly the same in nuance.

Because the sentence expresses motion toward a place.

In Croatian:

• na + accusative = movement onto/to
• na + locative = location at/on

So:

• na odredište = to the destination
• na odredištu = at the destination

Since they are arriving to a destination, the accusative is used.

It is accusative singular.

The noun odredište is a neuter noun, and in this case the nominative and accusative singular look the same:

• nominative: odredište
• accusative: odredište

So even though the form does not change, its grammatical role is accusative because it follows na in a direction/motion meaning: na odredište.

Because da se ne brinemo is a subordinate clause explaining the purpose or intention of the main action.

The structure is:

• main clause: Roditelji se javljaju čim stignu na odredište
• purpose clause: da se ne brinemo

So the comma separates the main statement from the clause meaning:

• so that we don’t worry
• so we won’t worry

This is normal Croatian punctuation.

Here da introduces a purpose clause.

It does not simply mean that in the basic English sense. In this sentence, it is closer to:

• so that
• so
• in order that

So:

• da se ne brinemo = so that we don’t worry

Croatian uses da in many different ways, and this is one of the most common ones.

After da in a purpose clause, Croatian commonly uses the present tense.

So:

• da se ne brinemo = so that we don’t worry

This is the normal structure. Croatian does not usually need an explicit future tense here.

A more literal English speaker might expect something like so that we will not worry, but Croatian naturally prefers the present after da in this kind of clause.

It refers to the people who would otherwise be worried — usually the speaker and at least one other person.

So the sentence shifts subjects:

• Roditelji = the parents
• brinemo se = we worry

This kind of subject change is completely normal. Croatian does not need to repeat the pronoun mi because the verb ending -mo already tells you it means we.

Yes, but it would add emphasis.

• da se ne brinemo = neutral, normal
• da se mi ne brinemo = so that we don’t worry with extra contrast or emphasis

You would use mi if you wanted to stress we as opposed to someone else. In ordinary speech, it is usually omitted because the verb ending already shows the subject.

They are related, but not identical.

• kad / kada = when
• čim = as soon as

So čim is more specific. It emphasizes immediacy: the second action happens right after the first one.

Compare:

• Kad stignu, javljaju se. = When they arrive, they contact us.
• Čim stignu, javljaju se. = As soon as they arrive, they contact us.

So čim is the better choice when the idea is immediately after arriving.

Because Croatian usually drops subject pronouns when they are already clear from the verb form.

In this sentence:

• javljaju tells you the subject is they
• stignu also tells you they
• brinemo tells you we

So Croatian does not need:

• oni
• mi

These pronouns are usually added only for emphasis, contrast, or clarity. This is one of the biggest differences from English.