Learn Hardcore Ukrainian: Чий це гаманець на столі?

Because чий must agree with the grammatical gender and number of the noun it modifies. Гаманець is masculine singular, so you use masculine singular чий.

Feminine: чия сумка?
Neuter: чиє пальто?
Plural: чиї ключі?

Why is it це and not цей?

це is a demonstrative pronoun used in identification sentences (“this is/it is”). It doesn’t change for gender/number in this use: Це мій гаманець. Це мої друзі.
цей/ця/це/ці are attributive determiners used directly before nouns: цей гаманець, ця сумка, ці гроші. In the question Чий це гаманець?, це means “this is.”

Where is the verb “to be”? Why isn’t there є?

In the present tense Ukrainian usually omits “to be.” So you say Чий це гаманець? (literally “Whose this wallet?”). Є appears for existence or emphasis: У мене є гаманець (“I have a wallet”), but not in simple identification: Це гаманець, not Це є гаманець.

Why is гаманець in the nominative and not гаманця?

With чий (“whose”) questions, the possessed noun stays in the nominative: чий гаманець. The possessor in the answer is often in the genitive: Це гаманець Оксани (“This is Oksana’s wallet”). You can also answer with a possessive adjective or pronoun: Це Оксанин гаманець / Це мій гаманець.

What case is на столі, and why столі?

На столі is the Locative (also called Prepositional) case. The preposition на + location takes the Locative. The noun стіл (table) changes to столі in the Locative, with the consonant softened before і.

What’s the difference between на столі and на стіл (and за столом)?

на столі = on the table (location, Locative): Гаманець на столі.
на стіл = onto the table (direction/motion, Accusative): Поклади гаманець на стіл.
за столом = at the table (Instrumental): Він сидить за столом.

Is the word order fixed? Can I say Це чий гаманець? or Чий гаманець це?

All three are grammatical:

Чий це гаманець? — neutral, most common.
Це чий гаманець? — also common in speech; can sound a bit more surprised/abrupt.
Чий гаманець це? — acceptable but a bit more bookish/marked in tone. Intonation shifts the emphasis more than word order here.

Can I drop це and just say Чий гаманець на столі?

Yes, but the nuance changes:

Чий це гаманець на столі? points to a specific wallet you’re indicating (“Whose is this wallet that’s on the table?”).
Чий гаманець на столі? asks about whichever wallet happens to be on the table (“Whose wallet is on the table?”) without the deictic “this.”

Is Чий цей гаманець (на столі)? correct?

It can occur in speech, especially when you strongly point to “this” particular wallet, but it’s less idiomatic than Чий це гаманець? because Ukrainian avoids stacking two determiners (чий + цей) before the same noun. Prefer Чий це гаманець?

How do I answer this question naturally?

Common answers:

With a pronoun: Це мій / твій / його / її / наш / ваш / їхній гаманець. (You can also say just Це мій, if the noun is obvious.)
With a name (genitive): Це гаманець Оксани / Івана.
With a possessive adjective from a name: Це Оксанин гаманець.
Negative: Це не мій.
If uncertain: Не знаю.

What are the main forms of чий I should know?

Masculine singular: чий (чий гаманець?)
Feminine singular: чия (чия сумка?)
Neuter singular: чиє (чиє пальто?)
Plural: чиї (чиї ключі?) These also decline by case, but for basic questions you most often meet the nominative forms above.

If I don’t name the object, how do I say “Whose is this?”

Use the neuter to match це: Чиє це? That’s the safest all-purpose form. If you already know the item’s gender/number, you can also say Чий це? / Чия це? / Чиї це?

How do you pronounce the words?

чий: roughly “chyi” with short i; IPA [t͡ʃɪj].
це: “tse”; IPA [t͡se].
гаманець: stress on the last syllable: ha-ma-NEts; IPA [ɦɑmɐˈnɛt͡sʲ]. Ukrainian г is a voiced “h,” not a hard “g.”
на столі: stress on the last syllable: na sto-LI; IPA [nɑ stoˈlʲi].

Are there articles like “a/the” in Ukrainian?

No. Ukrainian has no articles. Гаманець can mean “a wallet” or “the wallet,” depending on context.

Does це change in the plural?

In identification sentences, це stays це even with plurals: Це мої гаманці (“These are my wallets”). Use ці only when it directly modifies a noun: ці гаманці (“these wallets”).

Why does гаманець end in -ець with a soft sign?

The noun belongs to a common masculine pattern ending in -ець. The soft sign in -ць marks a soft [t͡sʲ] sound. Other examples: хлопець, палець, місяць.

Is there a more polite way to ask?

Yes. Add a polite opener:

Вибачте, чий це гаманець на столі?
Перепрошую, чий це гаманець на столі?

What’s the difference between using чий and asking with у кого?

Чий
- noun asks “whose” with agreement: Чий це гаманець?
У кого focuses on the possessor: У кого гаманець? / У кого на столі гаманець? (“Who has the wallet / whose place has a wallet on the table?”). It’s grammatical but a bit different in focus; for identifying an owner of a specific item you’re pointing at, чий is the most straightforward.