Vay, bu gerçekten büyük!

Vay is an interjection, like wow!, whoa!, or sometimes oh! in English. It shows surprise, admiration, shock, or strong reaction.

In Vay, bu gerçekten büyük!, it sounds like the speaker is reacting strongly to what they see.

Its exact feeling depends a lot on tone:

• Vay! = Wow!
• sometimes it can also sound like Oh no! or Goodness!, depending on context

It is common in spoken Turkish and very natural in exclamations.

In Turkish, the present-tense verb to be is often omitted in sentences like this.

So:

• Bu gerçekten büyük. literally looks like This really big.
• but it naturally means This is really big.

This is completely normal Turkish grammar. In simple present descriptive sentences, Turkish usually does not use a separate word for is.

Examples:

• Bu güzel. = This is beautiful.
• Ev büyük. = The house is big.

If you wanted another tense, Turkish would show it differently:

• Bu büyüktü. = This was big.
• Bu büyük olacak. = This will be big.

Yes, bu means this.

In this sentence, bu is acting as a pronoun, because it stands alone:

• Bu gerçekten büyük. = This is really big.

If it came before a noun, it would be a demonstrative adjective:

• bu ev = this house
• bu kitap = this book

So here, since there is no noun after bu, it means this by itself.

Gerçekten is an adverb. It usually means really, truly, or actually, depending on context.

Here it strengthens the adjective büyük:

• gerçekten büyük = really big

It often adds a sense of genuine reaction, not just degree. So it can feel a little like:

• This is genuinely big
• This is really big

It is very common in spoken and written Turkish.

Because gerçekten is modifying the adjective büyük, and in Turkish, adverbs commonly come before the word they modify.

So:

• gerçekten büyük = really big

That word order is very natural.

Turkish word order is somewhat flexible, but this is the most straightforward version for this sentence. Putting gerçekten before büyük makes it clear that really is describing big.

Turkish often puts the most important descriptive or predicate part near the end of the sentence.

In Bu gerçekten büyük, the final word büyük is the predicate adjective, so ending with it sounds natural and emphatic.

This is a common Turkish pattern:

• Bu güzel.
• O pahalı.
• Hava soğuk.

So ending with büyük is exactly what you would expect in Turkish.

No. Turkish adjectives do not agree with nouns for gender or number.

So büyük stays büyük whether the noun is singular or plural, masculine or feminine. Turkish does not have grammatical gender like many European languages do.

Examples:

• bu ev büyük = this house is big
• bu evler büyük = these houses are big
• o araba büyük = that car is big

The adjective stays the same.

Yes, you can definitely say Bu çok büyük!

The difference is:

• çok büyük = very big
• gerçekten büyük = really / truly big

In everyday English, both may translate as really big, but in Turkish they are not exactly the same.

Çok mainly expresses degree:

• very big

Gerçekten can express sincerity, reality, or strong reaction:

• really big
• genuinely big
• actually big

So:

• Bu çok büyük! sounds like a straightforward comment on size.
• Bu gerçekten büyük! sounds a bit more like surprise or emphasis.

A rough pronunciation guide is:

• Vay ≈ vye
• bu = boo
• gerçekten ≈ gehr-CHEK-ten
• büyük ≈ byoo-YOOK or bew-YOOK as an approximation

A few useful notes:

• ç is pronounced like ch
• ş would be sh, though it does not appear here
• ü is a front rounded vowel that English does not really have, so approximations are imperfect
• Turkish stress can vary, but for learners, saying the words clearly is more important than getting perfect stress immediately

Yes, the comma is natural because Vay is a separate exclamation, followed by the main sentence.

So:

• Vay, bu gerçekten büyük!

This is like English:

• Wow, this is really big!

In very casual writing, people may sometimes leave out punctuation, but with standard punctuation, the comma is a good choice.

Yes, it sounds natural and understandable.

It is a normal kind of exclamation in spoken Turkish, especially when reacting to something unexpectedly large.

Depending on tone and situation, native speakers might also say similar things such as:

• Vay, bu çok büyük!
• Aa, bu çok büyükmüş!
• Bu gerçekten çok büyük!

But your sentence is perfectly natural and correct.