Nadam se da se ne brineš zbog sastanka sutra.

Nadam se means I hope.

The verb is nadati se, which is a reflexive verb, so it normally appears with se. In Serbian, you simply learn it as a whole unit:

• nadati se = to hope

So:

• Nadam se = I hope
• Nadaš se = you hope
• Nada se = he/she hopes

The se here is not translated separately into English; it is just part of how the verb works in Serbian.

Here da introduces a subordinate clause, similar to English that.

So the structure is:

• Nadam se = I hope
• da se ne brineš... = that you are not worrying / that you’re not worried...

Very often in Serbian, after verbs like hope, think, know, want, etc., a clause with da is used.

So:

• Nadam se da... = I hope that...

In natural English, that is often omitted, but in Serbian da is normally kept.

Because they belong to two different reflexive verbs:

• Nadam se ← from nadati se = to hope
• brineš se ← from brinuti se = to worry

So the full sentence contains two separate reflexive verb forms:

• Nadam se = I hope
• da se ne brineš = that you are not worrying

Even though both use se, they are not doing the same job in one verb phrase; each se belongs to its own verb.

Brineš is the 2nd person singular present tense form of brinuti se.

Conjugation:

• ja se brinem = I worry
• ti se brineš = you worry
• on/ona se brine = he/she worries

So se ne brineš means you are not worrying or you’re not worried, depending on context.

Because Serbian usually drops subject pronouns when they are clear from the verb ending, ti is not needed here.

In Serbian, ne usually goes directly before the finite verb.

So:

• brineš = you worry
• ne brineš = you do not worry

Since se is a clitic, it often appears before the verb in these structures:

• se brineš
• se ne brineš

This word order can feel unusual to English speakers, but it is normal in Serbian clitic placement.

Because zbog requires the genitive case.

The noun is:

• sastanak = meeting

After zbog it changes to genitive:

• zbog sastanka = because of the meeting / about the meeting

So:

• zbog
  • genitive

This is a very common pattern in Serbian. A learner should remember zbog together with the genitive.

It can suggest either, depending on context.

Literally, zbog often means because of. But with verbs of worrying, it is commonly translated more naturally as about:

• brinuti se zbog nečega = to worry about something

So in this sentence:

• zbog sastanka = about the meeting

A very literal translation, because of the meeting, is not wrong structurally, but in natural English worry about the meeting sounds better.

Yes, sutra could go in other positions. Serbian word order is fairly flexible.

This sentence:

• Nadam se da se ne brineš zbog sastanka sutra.

most naturally means:

• I hope you’re not worrying about the meeting tomorrow.

Here sutra is understood with sastanka: the meeting tomorrow.

You could also hear:

• Nadam se da se sutra ne brineš zbog sastanka.
• Nadam se da se zbog sastanka sutra ne brineš.

But those versions may shift emphasis. The original is very natural and neutral.

In theory, word order can sometimes create ambiguity, but in this sentence the most natural reading is:

• the meeting tomorrow

That is because zbog sastanka sutra is easily understood as one time-related phrase: about tomorrow’s meeting.

If someone wanted to say I hope you won’t be worrying tomorrow, they would usually choose a different structure to make that clearer.

Because Serbian often omits subject pronouns when the verb ending already shows the person.

Here brineš already tells you the subject is you singular.

So:

• se ne brineš = you are not worrying

You could add ti for emphasis:

• Nadam se da se ti ne brineš zbog sastanka sutra.

But that would sound more contrastive, as if you mean I hope you, specifically, are not worried.

It is informal singular, because of brineš.

That form is used when speaking to:

• one friend
• one family member
• one person you address with ti

For formal singular or plural you, Serbian would use brinete:

• Nadam se da se ne brinete zbog sastanka sutra.

That can mean either:

• I hope you are not worrying about the meeting tomorrow — formal singular
• I hope you all are not worrying about the meeting tomorrow — plural

Yes, brinuti se is a very common and neutral way to say to worry.

Some related expressions are:

• brinuti se zbog nečega = to worry about something
• biti zabrinut = to be worried / concerned
• ne brini = don’t worry

So this sentence sounds natural and everyday. It does not sound overly formal or literary.

A helpful breakdown is:

• Nadam se = I hope
• da = that
• se ne brineš = you are not worrying / you’re not worried
• zbog sastanka = about the meeting
• sutra = tomorrow

More naturally as a whole:

• I hope you’re not worried about tomorrow’s meeting.

That natural English wording often matches the Serbian sense better than a very literal translation.