To nie jest oryginał, tylko reprodukcja.

Here to means something like this, that, or it, depending on context.

In sentences like To jest... / To nie jest..., Polish very often uses to to identify or classify something:

• To jest mój dom. = This/That is my house.
• To nie jest obraz. = This/That is not a painting.

So in To nie jest oryginał..., to is the thing being pointed out or discussed.

Jest is the 3rd person singular form of być (to be), meaning is.

Because the sentence starts with to, the verb stays singular:

• To jest oryginał. = This/That is an original.
• To nie jest reprodukcja. = This/That is not a reproduction.

So jest is simply the normal form for is here.

This is a very common question, because learners often learn that after być (to be), Polish can use the instrumental case:

• On jest lekarzem. = He is a doctor.

But with the structure to jest / to nie jest + noun, Polish usually uses the nominative case instead:

• To jest lekarz.
• To nie jest problem.
• To nie jest oryginał, tylko reprodukcja.

So in this sentence, oryginał and reprodukcja are in the nominative because this is an identifying sentence with to.

Polish usually negates a verb by putting nie before it.

So:

• jest = is
• nie jest = is not

That gives:

• To jest oryginał. = This is an original.
• To nie jest oryginał. = This is not an original.

So nie is the standard way to make the verb negative here.

Here tylko means but, but rather, or only/just in the sense of correcting what came before.

The pattern is:

nie X, tylko Y = not X, but Y

So:

• To nie jest oryginał, tylko reprodukcja. = This is not an original, but a reproduction.

This is a very common Polish structure used to correct a mistaken assumption.

Because tylko is connecting two contrasting parts of the sentence:

• nie jest oryginał
• reprodukcja

In Polish, a comma is normally used before conjunctions like tylko when they introduce this kind of contrast.

So the comma in:

To nie jest oryginał, tylko reprodukcja.

is standard punctuation.

Sometimes Polish does use ale for but, but in this kind of correction, tylko is the most natural choice.

The pattern nie..., tylko... is very standard when you mean:

• not this one, but that one
• not X, but Y

So:

• To nie jest oryginał, tylko reprodukcja. = the most natural version

Using ale might be understandable in some contexts, but tylko is the better choice here because it clearly corrects the first idea.

Not exactly.

• reprodukcja = reproduction
• kopia = copy

They are related, but reprodukcja often sounds a bit more formal or more specific, especially in art, printing, photography, or museum contexts.

For example, if you are talking about a painting in a gallery shop, reprodukcja is very natural.
If you are talking about a duplicate of a document or file, kopia is often more natural.

So in this sentence, reprodukcja suggests that the object is not the original work, but a reproduced version of it.

Because Polish does not have articles.

English distinguishes between:

• an original
• the original
• a reproduction
• the reproduction

Polish usually leaves that information to context.

So:

• oryginał can mean an original or the original
• reprodukcja can mean a reproduction or the reproduction

You understand which one is meant from the situation, not from an article.

A rough pronunciation guide:

• oryginał ≈ o-ri-GHI-now
• reprodukcja ≈ re-pro-DOOK-tsya

A few useful points:

• Polish stress is usually on the second-to-last syllable
  • orygiNAŁ
  • reproDUKcja
• ł sounds like English w
  • so oryginał ends a bit like now
• cj in reprodukcja sounds like tsy / tsya

You do not need to make it sound exactly English-like; the key is getting the stress and the ł right.

Yes, Polish word order is fairly flexible, but this version is the most neutral and natural:

To nie jest oryginał, tylko reprodukcja.

You can change word order in some contexts for emphasis, but beginners should usually stick to the standard pattern:

To nie jest X, tylko Y.

That pattern is very useful and easy to reuse, for example:

• To nie jest kot, tylko pies.
• To nie jest problem, tylko pytanie.
• To nie jest Anna, tylko Maria.