Czy ta parasolka jest twoja?

Czy is a particle used to turn a statement into a yes/no question.

So:

• Ta parasolka jest twoja. = This umbrella is yours.
• Czy ta parasolka jest twoja? = Is this umbrella yours?

It does not mean what, whether, or if in the same way English words do in every context. In this sentence, its job is simply to mark a yes/no question.

Because parasolka is a feminine noun in Polish.

Polish demonstratives change for gender:

• ten = this (masculine)
• ta = this (feminine)
• to = this (neuter)

Since parasolka is feminine, you say:

• ta parasolka = this umbrella

For the same reason: twoja has to agree with parasolka, which is feminine.

The possessive your in Polish changes form:

• twój = your (masculine)
• twoja = your (feminine)
• twoje = your (neuter)

So:

• ten telefon jest twój = this phone is yours
• ta parasolka jest twoja = this umbrella is yours
• to krzesło jest twoje = this chair is yours

Yes, parasolka is the usual everyday word for umbrella.

There is also parasol, but that often refers more to a sunshade/parasol, though in some contexts people may use it more broadly. For most learners, parasolka is the safest and most natural word for umbrella in everyday speech.

Also, -ka is often a diminutive ending in Polish, and historically parasolka is related to that pattern, but in modern usage it is simply the standard everyday word.

Because in Polish, just like in English, you can leave the noun out when it is already understood.

So:

• Czy ta parasolka jest twoja? = Is this umbrella yours?

Literally, twoja here means something like your one / yours.

You could also say:

• Czy to twoja parasolka? = Is this your umbrella?

That version keeps the noun after the possessive.

In the present tense, Polish normally does use jest in sentences like this.

So:

• Ta parasolka jest twoja. = correct
• Czy ta parasolka jest twoja? = correct

Omitting jest here would sound unnatural or incomplete in standard Polish.

Polish sometimes drops words that English keeps, but in this kind of equational sentence (X is yours), jest is normally needed.

Yes. In spoken Polish, you can often ask a yes/no question just with intonation:

• Ta parasolka jest twoja?

That also means Is this umbrella yours?

The version with czy is a bit clearer and explicitly marks the sentence as a question:

• Czy ta parasolka jest twoja?

Both are natural.

Both can mean almost the same thing:

• Czy ta parasolka jest twoja? = Is this umbrella yours?
• Czy to twoja parasolka? = Is this your umbrella?

The difference is mainly in structure and emphasis:

• ta parasolka focuses on this umbrella
• to twoja parasolka focuses a bit more on identifying the object as your umbrella

In everyday conversation, both are very common and natural.

It is in the nominative case.

That is because parasolka is the subject of the sentence:

• Ta parasolka = the thing being talked about

This is true even though the sentence is a question. A question does not automatically change the case.

So:

• ta parasolka = nominative
• jest twoja = is yours

A rough pronunciation guide for an English speaker:

• Czy ≈ chi (but with a harder Polish cz sound, like ch in chop)
• ta = tah
• parasolka ≈ pa-ra-SOL-ka
• jest ≈ yest
• twoja ≈ TVO-ya

A fuller approximation:

chy tah pa-ra-SOL-ka yest TVO-ya?

A few useful sound notes:

• cz in czy is one sound, like English ch, but usually a bit harder
• j in Polish sounds like English y
• w in Polish sounds like English v, so twoja starts more like tvo-
• stress in Polish is usually on the second-to-last syllable, so:
  • paraSOLka
  • twoJA

Yes, twoja is based on ty, the informal singular you.

If you need a polite/formal version, Polish usually uses forms based on pan / pani:

• to a man: Czy ta parasolka jest pana? = Is this umbrella yours, sir?
• to a woman: Czy ta parasolka jest pani? = Is this umbrella yours, ma’am?

You can also hear:

• Czy to pana parasolka?
• Czy to pani parasolka?

These are very common polite ways to ask.

Yes. In natural English, Is this umbrella yours? and Is this your umbrella? are very close in meaning.

Polish often uses a structure that literally matches Is this umbrella yours?:

• Czy ta parasolka jest twoja?

But when translating naturally, English speakers may also say:

• Is this your umbrella?

So the Polish sentence can correspond to either of those English versions, depending on context.

Formally, it is the possessive form agreeing with a feminine noun, so it behaves like a possessive adjective in many ways. But in this sentence it stands without the noun, so functionally it is like a possessive pronoun in English:

• twoja = yours

That is why learners often think of it as:

• adjective form: twoja parasolka = your umbrella
• pronoun-like use: jest twoja = is yours

Both ways of thinking are useful.

Yes, Polish word order is fairly flexible, though some versions sound more natural than others.

The most neutral version is:

• Czy ta parasolka jest twoja?

You might also hear:

• Ta parasolka jest twoja?
• Czy twoja jest ta parasolka? — possible, but much less neutral and more marked/emphatic

For learners, it is best to stick with:

• Czy ta parasolka jest twoja?

It is clear, natural, and standard.