Voditelj može poništiti odlučujuće pitanje kao da nagrada nije važna.

Voditelj most often means host, presenter, or moderator, depending on context.

In this sentence, the most natural translation is probably host or presenter, especially if the sentence is about a quiz show, TV show, or competition.

The noun is masculine singular nominative, and it is the subject of the sentence.

Because moći means can / to be able to, and in Croatian it is followed by an infinitive.

So:

• može = can
• poništiti = to cancel / to invalidate / to annul

Together:

• može poništiti = can cancel / can invalidate

This is very normal Croatian structure:

• Mogu doći. = I can come.
• Može pomoći. = He/She can help.
• Voditelj može poništiti... = The host can cancel/invalidate...

Poništiti means to cancel, to invalidate, to annul, or to void.

In this sentence, it suggests that the host can make the question no longer count or no longer be valid.

A useful nuance:

• otkazati often means cancel in the sense of calling something off
• poništiti often means invalidate or nullify something officially or formally

So for a question, answer, vote, result, or decision, poništiti is a very natural verb.

Also, poništiti is perfective, so it refers to a completed action: to invalidate it fully.

Because odlučujuće is an adjective agreeing with pitanje.

• pitanje = question
• odlučujući / odlučujuća / odlučujuće = decisive / deciding

Since pitanje is neuter singular, the adjective must also be neuter singular:

• masculine: odlučujući
• feminine: odlučujuća
• neuter: odlučujuće

So:

• odlučujuće pitanje = the decisive question / the deciding question

Here it is accusative singular, because it is the direct object of poništiti.

The host is invalidating what? → odlučujuće pitanje

But for many neuter singular nouns in Croatian, the nominative and accusative forms are identical.

So:

• nominative: pitanje
• accusative: pitanje

That is why it looks the same.

The same is true for the adjective here:

• nominative neuter singular: odlučujuće
• accusative neuter singular: odlučujuće

So the whole phrase keeps the same form.

Kao da means as if.

It introduces a comparison to something apparent, imagined, or not necessarily real.

So:

• kao da nagrada nije važna = as if the prize is not important
  or in more natural English,
• as if the prize were not important

Very common examples:

• Gleda me kao da me poznaje. = He/She looks at me as if he/she knows me.
• Priča kao da je stručnjak. = He/She talks as if he/she were an expert.

So in your sentence, the host acts in a way that suggests the prize does not matter.

Because važna must agree with nagrada.

• nagrada = prize
• nagrada is feminine singular
• therefore the adjective must also be feminine singular

So:

• masculine: važan
• feminine: važna
• neuter: važno

That gives:

• nagrada nije važna = the prize is not important

If the noun were neuter, then you would use važno:

• Pitanje nije važno. = The question is not important.

This is a very common question, because Croatian and English work differently here.

Croatian does not have a special subjunctive form like English were in as if it were not important.

Instead, after kao da, Croatian usually uses an ordinary finite verb form, often in the present tense if the meaning is general or current.

So:

• kao da nagrada nije važna literally: as if the prize is not important

But in natural English, this is often translated as:

• as if the prize were not important

So the difference is grammatical, not a big difference in meaning.

Because nagrada is the subject of the subordinate clause:

• nagrada nije važna = the prize is not important

In that clause:

• nagrada = subject
• nije = verb
• važna = predicate adjective

Subjects are normally in the nominative, so nagrada stays nominative.

Yes, Croatian word order is fairly flexible, though some orders sound more natural than others.

The original order is neutral and clear:

• Voditelj može poništiti odlučujuće pitanje kao da nagrada nije važna.

You could also hear variations such as:

• Voditelj može kao da nagrada nije važna poništiti odlučujuće pitanje.

But that sounds more marked or stylistically unusual.

In everyday Croatian, the original version is the best choice because it is smooth and easy to understand.

So the short answer is:

• yes, word order can change
• but this sentence already uses the most natural neutral order

Not exactly.

Odlučujuće means decisive, determining, or the one that decides the outcome.

So:

• važno pitanje = important question
• odlučujuće pitanje = decisive question / the question that decides everything

In a quiz or competition, odlučujuće pitanje is the question that determines who wins.

So it is often more specific than just important.

Yes. Voditelj can mean several related things depending on context:

• host / presenter on TV or radio
• leader
• manager
• moderator
• person in charge

The core idea is someone who leads or conducts something.

In this sentence, because of question and prize, host is probably the best interpretation.

The sentence breaks down like this:

• Voditelj = subject
• može poništiti = verb phrase
• odlučujuće pitanje = direct object
• kao da nagrada nije važna = comparison clause, as if the prize were not important

So the pattern is:

Subject + modal + infinitive + object + kao da clause

That makes the sentence easier to read:

• Voditelj
• može poništiti
• odlučujuće pitanje
• kao da nagrada nije važna

This is a useful way to analyze longer Croatian sentences.