Ovaj znak je važan.

Because znak is a masculine singular noun in Serbian.

The demonstrative this changes to match the noun’s:

• gender
• number
• case

In the nominative singular:

• ovaj = this (masculine)
• ova = this (feminine)
• ovo = this (neuter)

So:

• ovaj znak = this sign
• ova knjiga = this book
• ovo selo = this village

In this sentence, you can tell from the form of the words around it:

• ovaj is masculine singular
• važan is also masculine singular

So they both agree with znak.

More generally, many Serbian nouns ending in a consonant are masculine, and znak ends in a consonant. That is a very common pattern:

• grad = city
• pas = dog
• znak = sign

But agreement in the sentence is often the safest clue.

Je is the 3rd person singular form of the verb biti = to be.

So:

• je = is

In the present tense, Serbian usually keeps the verb to be in this kind of sentence:

• Ovaj znak je važan. = This sign is important.

You generally should not leave it out in a normal statement like this.

Because the adjective must agree with znak.

Znak is:

• masculine
• singular
• nominative

So the adjective also appears in the masculine singular nominative form:

• važan = important (masculine singular)

Compare:

• ovaj znak je važan = this sign is important
• ova poruka je važna = this message is important
• ovo pravilo je važno = this rule is important
• ovi znakovi su važni = these signs are important

That is one common masculine adjective ending in Serbian.

Many adjectives in the dictionary are given in the masculine singular form, and some of them end in:

• -an
• -en
• just a consonant, depending on the adjective

For važan, the base form is:

• važan (masculine)
• važna (feminine)
• važno (neuter)

So the -an is simply part of the correct masculine singular form here.

Yes, it is in the nominative case, because it is the subject of the sentence.

The sentence structure is:

• Ovaj znak = subject
• je važan = predicate

You can also tell by the forms:

• ovaj is the masculine singular nominative form
• znak is in its basic subject form
• važan matches that nominative subject

If the noun were in another case, ovaj would change too. For example:

• Vidim ovaj znak. = I see this sign.

In that example, the noun phrase still looks the same because masculine inanimate accusative often matches nominative. But in other genders or with animate nouns, the form may change more visibly.

The neutral, most straightforward word order is:

• Ovaj znak je važan.

Yes, you can say:

• Važan je ovaj znak.

But that changes the emphasis. It sounds more like:

• It is this sign that is important or
• This sign is important with extra focus on important or on this sign

So:

• Ovaj znak je važan. = neutral
• Važan je ovaj znak. = marked/emphatic

A simple approximation is:

• ovaj ≈ OH-vai

More carefully:

• o as in a pure short o
• v like English v
• aj sounds roughly like eye

So the whole word sounds close to OH-vye or OH-vai, depending on how you approximate it in English.

Serbian pronunciation is fairly phonetic, so it is usually pronounced as written.

Yes, the z is pronounced.

Znak is roughly:

• znahk

The beginning zn- may feel unusual to an English speaker, but Serbian allows that consonant cluster naturally.

Try saying:

• z
  • nak
• then blend it: znak

The a is like a clear a sound, and the final k is pronounced clearly.

Važan is roughly pronounced:

• VAH-zhan

The letter ž sounds like the s in measure or the g in genre.

So:

• v = v
• a = open a
• ž = the sound in measure
• an = ahn

A rough English-friendly guide:

• VAH-zhahn

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

So Serbian simply says:

• ovaj znak = this sign

And more generally:

• znak can mean a sign or the sign, depending on context
• ovaj znak specifically means this sign

English needs articles; Serbian does not.

Yes. Znak is a flexible word and can mean:

• sign
• symbol
• mark
• signal
• sometimes indication

The exact meaning depends on context.

So in different situations:

• traffic context: sign
• writing/system context: symbol
• evidence context: sign/indication

In this sentence, the intended meaning is already given, but it is useful to know the word is broader than just one English translation.

Yes.

• Ovaj znak je važan. = This sign is important.
• Znak je važan. = The sign is important / A sign is important, depending on context.

Including ovaj makes the reference more specific and points to a particular sign:

• this sign

Without it, the sentence is more general or depends more on context.

The plural would be:

• Ovi znakovi su važni. = These signs are important.

Notice all the changes:

• ovaj → ovi
• znak → znakovi
• je → su
• važan → važni

This shows Serbian agreement very clearly: demonstrative, noun, verb, and adjective all work together.