Nazočnost tumača je važna.

• nazočnost = presence; a feminine singular nominative noun
• tumača = of the interpreter; genitive singular of tumač
• je = is; 3rd person singular of biti (to be)
• važna = important; a feminine singular adjective

So the structure is literally Presence of the interpreter is important.

Because Croatian often expresses of X with the genitive.

Here, nazočnost tumača means the presence of the interpreter.
The base noun is tumač (interpreter), and its genitive singular form is tumača.

This is very normal in Croatian:

• prisutnost gosta = the presence of the guest
• dolazak liječnika = the arrival of the doctor

Because važna has to agree with nazočnost, and nazočnost is feminine singular.

In Croatian, adjectives agree with the noun in gender, number, and usually case.

So:

• važan = masculine singular
• važna = feminine singular
• važno = neuter singular

Since nazočnost is feminine, the correct form is važna.

It is in the nominative singular.

That is because it is the subject of the sentence: the thing being described as important.

So:

• Nazočnost = the subject
• je važna = is important

Nazočnost is correct, but it sounds a bit formal or administrative to many learners.

A very common alternative is prisutnost:

• Prisutnost tumača je važna.

This also means The interpreter’s presence is important.

In many everyday contexts, prisutnost may sound more natural, while nazočnost can feel slightly more official.

Usually tumač means interpreter, especially someone who interprets speech.

But the word can also have broader meanings such as:

• interpreter
• commentator
• explainer

For translator in the written sense, Croatian more often uses:

• prevoditelj
• sometimes prevodilac (depending on region/style)

One thing that can confuse learners: sudski tumač is an official term that can refer to a court-certified language professional, often covering translation and interpreting in legal settings.

Because Croatian does not have articles like English the and a/an.

So tumača can mean:

• of the interpreter
• of an interpreter

The exact meaning depends on the context.

The same is true for the whole sentence: depending on context, it could be understood as either:

• The interpreter’s presence is important
• An interpreter’s presence is important

Yes. Croatian word order is more flexible than English.

The version Nazočnost tumača je važna is natural and neutral.
But you could also say:

• Važna je nazočnost tumača.

This puts more focus on važna (important).

So both are correct, but the emphasis changes slightly.

Yes, you can.

• nazočnost tumača = the presence of the interpreter
• tumačeva nazočnost = the interpreter’s presence

Both are correct. The first uses a genitive noun; the second uses a possessive adjective.

In many contexts, nazočnost tumača sounds a bit more neutral and straightforward.
Tumačeva nazočnost is also perfectly good, but it may sound slightly more marked or personal.

In a normal full sentence, yes.

Je is the present-tense form of biti (to be), so it works like is in English.

• Nazočnost tumača je važna. = correct full sentence

If you remove je, it may sound like a heading, note, or a very compressed style, not a normal standard sentence.

The main sounds English speakers usually notice are:

• č in tumača and nazočnost
  This is like ch in church, but usually a bit firmer.

• ž in važna
  This sounds like the s in measure or the g in genre.

A rough English-friendly pronunciation might be:

na-ZOH-chnost too-MAH-cha ye VAZH-na

That is only an approximation, but it is good enough to start.