Slavljenik ne zna tajnu.

Slavljenik means the person being celebrated or the celebrant. In everyday Serbian, it is very often used for the birthday person, but it can also be used more generally for someone whose special occasion is being celebrated.

It is a masculine noun. The usual feminine form is slavljenica.

Slavljenik is in the nominative singular because it is the subject of the sentence.

In other words:

• slavljenik = the person doing the action
• tajnu = the thing affected by the action

So Serbian marks:

• subject → nominative
• direct object → usually accusative

Because tajnu is the accusative singular form of tajna.

The noun tajna means secret, and in this sentence it is the direct object of zna (knows), so Serbian uses the accusative form:

• tajna = nominative singular
• tajnu = accusative singular

Compare:

• Tajna je važna. = The secret is important.
• Zna tajnu. = He/She knows the secret.

Serbian usually forms negation by putting ne before the verb.

So:

• zna = knows
• ne zna = does not know / doesn’t know

With most verbs, ne is written as a separate word, as it is here:

• ne znam
• ne znaš
• ne zna

A few very common verbs have special fused negative forms, but znati is not one of them.

The verb is zna because slavljenik is third person singular: he knows / he does not know.

The infinitive is znati = to know. Its present tense is:

• ja znam = I know
• ti znaš = you know
• on/ona/ono zna = he/she/it knows
• mi znamo = we know
• vi znate = you know
• oni/one/ona znaju = they know

So slavljenik ne zna is the correct form for the celebrant doesn’t know.

Because Serbian has no articles like English a/an/the.

That means tajnu can mean:

• a secret
• the secret

And slavljenik can mean:

• a celebrant
• the celebrant

The exact meaning depends on context, not on an article.

Yes. Serbian word order is more flexible than English word order because case endings help show who is doing what.

The most neutral version is:

• Slavljenik ne zna tajnu.

But other orders are possible for emphasis, for example:

• Tajnu slavljenik ne zna. → emphasizes the secret
• Slavljenik tajnu ne zna. → also possible, slightly marked
• Ne zna slavljenik tajnu. → more stylistic or context-dependent

So the original sentence is the most natural default order, but it is not the only possible one.

Yes. Serbian often leaves out the subject when it is clear from context, because the verb ending already shows person and number.

So you could also say:

• Ne zna tajnu. = He/She doesn’t know the secret.

In this sentence, slavljenik is included to make the subject explicit.

A rough English-style pronunciation is:

SLAHV-lye-nik neh ZNAH TAI-noo

A few useful pronunciation notes:

• lj in slavljenik is a soft sound, similar to the lli in million for many English speakers
• j is pronounced like English y
• z is always z
• aj sounds like eye

Serbian spelling is fairly phonetic, so words are usually pronounced close to how they are written.