Şans önemli.

In Turkish, the verb to be is often left out in the present tense when one noun or adjective is describing another.

So:

• Şans önemli. = Luck is important.

This is completely normal Turkish.

If you want a more formal, emphatic, or written style, you can add -dir:

• Şans önemlidir.

Both are correct, but Şans önemli is the more natural everyday version.

Önemli is an adjective, meaning important.

In this sentence, it works as the predicate adjective:

• Şans = luck
• önemli = important

So the structure is basically:

• [noun] + [adjective]

This is a very common pattern in Turkish:

• Hava güzel. = The weather is nice.
• Bu zor. = This is difficult.
• Şans önemli. = Luck is important.

In Turkish, when an adjective is the main statement of the sentence, it usually comes after the noun.

So:

• Şans önemli. = Luck is important.

But if the adjective directly describes a noun inside a noun phrase, it usually comes before the noun:

• önemli şans = important luck

That second phrase is grammatically possible, but it sounds less natural as a complete thought. It is just a noun phrase, not a full statement in the same way.

So:

• Şans önemli. = full sentence
• önemli şans = noun phrase

Not if you mean Luck is important.

Önemli şans means something like important luck, which is a noun phrase, not the same sentence.

To make a full sentence meaning Luck is important, Turkish uses:

• Şans önemli.

This difference is important:

• güzel ev = beautiful house
• Ev güzel. = The house is beautiful.

So word order changes the function.

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

So şans on its own can mean:

• luck
• the luck
• luck in general

In Şans önemli, it is understood as a general statement: Luck is important.

Turkish often leaves this kind of thing to context.

A helpful approximate pronunciation is:

• Şans ≈ shahns
• önemli ≈ uh-NEM-lee or oe-NEM-lee

A few key sounds:

• ş = sh as in shoe
• ö = a rounded vowel that English does not really have; it is similar to German ö or French eu
• c in Turkish is pronounced like English j, but there is no c in this sentence

Stress-wise, önemli is usually stressed around the second syllable: ö-NEM-li.

The word önemli comes from:

• önem = importance
• -li = a suffix meaning something like with, having, or characterized by

So önemli literally means something like having importance.

This suffix is very common in Turkish:

• tuz = salt → tuzlu = salty
• ses = sound/voice → sesli = with sound, voiced
• renk = color → renkli = colorful

So önemli is built in a very typical Turkish way.

Yes, absolutely.

• Şans önemli. = Luck is important.
• Şans çok önemli. = Luck is very important.

Here, çok means very.

This is a very common way to strengthen adjectives in Turkish.

For adjective and noun sentences like this, Turkish usually makes the negative with değil.

So:

• Şans önemli değil. = Luck is not important.

Notice that Turkish does not add something like English not to a verb here, because there is no separate present-tense is in the sentence.

For the past tense, Turkish adds a past form of to be to the predicate:

• Şans önemliydi. = Luck was important.

This is made from:

• önemli
  • ydi

Similarly:

• Şans önemli değil. = Luck is not important.
• Şans önemli değildi. = Luck was not important.

Önemlidir is a more formal or emphatic version.

So:

• Şans önemli. = natural, everyday
• Şans önemlidir. = more formal, written, textbook-like, or emphatic

You may see -dir in:

• definitions
• academic writing
• formal statements
• proverbs or general truths

In ordinary conversation, people often leave it out.

It is grammatically singular, but it refers to luck in general, which is often treated like an uncountable idea in English too.

If you wanted the plural chances/lucky breaks, that would be different:

• şanslar

But in Şans önemli, the meaning is the general concept luck, not multiple separate chances.