Это важный знак.

In Russian, the verb to be is usually left out in the present tense.

So:

• Это важный знак = This is an important sign
• literally: This important sign

Russian speakers understand the is automatically.

But in other tenses, forms of to be do appear:

• Это был важный знак = This was an important sign
• Это будет важный знак = This will be an important sign

Это is very common and can mean this, that, or sometimes it, depending on context.

In this sentence, это introduces or identifies something:

• Это важный знак = This/That is an important sign

A useful thing to know: in sentences like this, это often works a bit like this is or that is.

Compare:

• Это знак = This is a sign
• Это важно = This is important

So here это is pointing to something and identifying it.

Because Russian adjectives must agree with the noun they describe in:

• gender
• number
• case

The noun знак is:

• masculine
• singular
• nominative

So the adjective must match it:

• важный знак = important sign

Other forms would be:

• важная книга = important book
• важное слово = important word
• важные знаки = important signs

A very common rule is:

• nouns ending in a consonant are usually masculine

Since знак ends in a consonant, it is masculine.

That is why the adjective takes the masculine form:

• важный знак

If it were neuter, for example, you would get:

• важное слово

If it were feminine:

• важная идея

They are in the nominative singular.

Why? Because this sentence is identifying something:

• Это важный знак = This is an important sign

The noun after это is often in the nominative when you are simply naming or identifying what something is.

So:

• знак = nominative singular
• важный = nominative singular masculine, matching знак

In Russian, adjectives usually come before the noun they describe, just like in English.

So:

• важный знак = important sign

This is the normal order.

Russian word order is more flexible than English, but the basic adjective + noun pattern is standard. You may see different word order for emphasis in longer sentences, but важный знак is the natural form here.

A simple pronunciation guide is:

• Это = EH-tuh
• важный = VAZH-nyy
• знак = znak

Stress:

• Э́то
• ва́жный
• знак (one syllable, so the stress is on that syllable)

A rough full pronunciation: EH-tuh VAZH-nyy znak

A useful note: in важный, the жн combination can feel a little tricky for English speakers. Say it slowly first:

• важ-ный

They are close, but not exactly the same in feeling.

• Это важный знак = This/That is an important sign
• Этот знак важный = This sign is important

The first sentence identifies something as an important sign.
The second starts with this sign and then says something about it.

Also notice the difference between это and этот:

• это = this/that/it in a general identifying sense
• этот = this and it must agree with the noun

Since знак is masculine:

• этот знак = this sign

This is a very common beginner question.

• это is often used in sentences like This is ... / That is ...
• этот is a demonstrative adjective meaning this, and it must match the noun

Compare:

• Это знак = This is a sign
• Этот знак = this sign

So in your sentence:

• Это важный знак = This is an important sign

If you wanted this important sign, you would say:

• этот важный знак

Not only. Знак has a fairly broad meaning range, depending on context. It can mean:

• a sign
• a symbol
• a mark
• a signal
• sometimes even a road sign

So важный знак could mean:

• an important sign
• an important signal
• an important indication

The exact English translation depends on the situation.

Yes, often it can.

Russian это does not always make the same near/far distinction that English makes with this and that. Context usually tells you what sounds best in English.

So Это важный знак could be translated as:

• This is an important sign
• That is an important sign

depending on what the speaker is pointing to or talking about.

A more explicit version is:

• Этот знак важный = This sign is important

But very often Russian prefers:

• Это важный знак when identifying something
• Этот знак очень важен = This sign is very important

Notice another useful pattern here:

• важный = important as an adjective before a noun
• важен = short-form adjective, often used as the predicate: is important

So:

• важный знак = an important sign
• знак важен = the sign is important