Bu sadece şanstı.

Bu usually means this, but in natural English translations it can also come out as that or even it, depending on context.

So Bu sadece şanstı can mean:

• This was just luck
• That was just luck
• It was just luck

Turkish often uses bu where English would choose among this/that/it based on the situation.

Sadece means only, just, or simply.

In this sentence, it adds the idea that there was nothing special or intentional about it:

• Bu şanstı = This/that was luck.
• Bu sadece şanstı = This/that was just luck.

A close synonym is yalnızca.

Şans means luck or chance.

In şanstı, the ending -tı is added to show was:

• şans = luck
• şans + tı = şanstı = was luck

So the sentence is built like this:

• Bu = this/that/it
• sadece = just
• şanstı = was luck

Together: This/that/it was just luck.

It is inside şanstı.

Turkish often does not use a separate word like is/was in the same way English does. With nouns and adjectives, Turkish adds a copula ending instead.

Here:

• şans = luck
• -tı = was

So şanstı literally works like it was luck.

This is because of a sound rule.

The past copula has forms like:

• -dı
• -di
• -du
• -dü and after voiceless consonants, it changes to:
• -tı
• -ti
• -tu
• -tü

Since şans ends in s, which is a voiceless consonant, d becomes t.

Also, the vowel becomes ı because of vowel harmony:

• the last vowel in şans is a
• so the suffix uses ı

That is why:

• şans + dı does not happen
• şans + tı = şanstı

Turkish does not use articles the same way English does.

English often needs a/an/the, but Turkish often leaves them out unless they are really needed.

So:

• şans = luck
• bir şans = a chance / one chance / a piece of luck, depending on context

In Bu sadece şanstı, leaving out bir sounds natural because luck is being used as a general abstract idea.

Yes, completely.

Turkish can make very compact sentences. This one has everything it needs:

• Bu = subject
• sadece = adverb
• şanstı = predicate with past meaning

So even though it is short, it is a full sentence.

Turkish usually puts the main predicate at the end of the sentence.

So the basic structure here is:

• Bu = subject/topic
• sadece = modifier
• şanstı = predicate

That final position for şanstı is very normal in Turkish.

If you change the order, you may change the emphasis. For example:

• Bu sadece şanstı = neutral, natural
• Sadece bu şanstı = more like Only this was luck
• Şanstı bu = marked/emphatic, less neutral

Yes. Yalnızca and sadece are both common words meaning only/just.

So these are both fine:

• Bu sadece şanstı
• Bu yalnızca şanstı

Sadece is often felt to be a bit more everyday and common in speech.

A rough pronunciation is:

shahn-stuh

More specifically:

• ş = sh as in shoe
• a = like a in father
• n s t are pronounced clearly
• ı is the Turkish dotless i, a sound English does not have exactly; it is somewhat like a relaxed uh sound made without rounding your lips

So:

• şans ≈ shahns
• şanstı ≈ shahn-stuh

They are different kinds of words:

• şans = luck
• şanslı = lucky

So:

• Bu sadece şanstı = This was just luck.
• Bu kişi şanslıydı = This person was lucky.

A learner may confuse them because they are related, but şans is a noun and şanslı is an adjective.

Yes, very often.

Bu sadece şanstı can be used when someone wants to say:

• it was not skill
• it was not planned
• it was not a big achievement
• success happened by accident

So depending on tone, it can sound:

• modest: I just got lucky
• dismissive: It was nothing special
• explanatory: There was no real reason; it was just luck

In the present tense, it would be:

Bu sadece şans.

That means:

• This/that is just luck
• It is just luck

In Turkish, present-tense nominal sentences often have no separate word for is.

Compare:

• Bu sadece şans. = This is just luck.
• Bu sadece şanstı. = This was just luck.

So the past meaning appears when the copula ending -tı is added.