Interrogative pronouns "który" (which) and "czyj" (whose) in subordinate clauses

What do these pronouns mean?

• który = which (choosing / identifying one or more items from a set).


• Example (direct question): Który pociąg odjeżdża o 10? (Which train leaves at 10?)


• Example (subordinate): Nie wiem, który pociąg odjeżdża o 10. (I don't know which train leaves at 10.)

• czyj = whose (asking about the owner/possessor of something).
• Example (direct): Czyj to jest rower? (Whose bicycle is this?)
• Example (subordinate): Nie wiem, czyj to jest rower. (I don't know whose bicycle this is.)

When do I use them in subordinate clauses?

• Use them in indirect (embedded) questions after verbs like: nie wiem, zastanawiam się, powiedz mi, zapytaj go, chciałbym wiedzieć.


• Powiedz mi, który film chcesz oglądać. (Tell me which film you want to watch.)


• Zastanawiam się, czyj to telefon leży na stole. (I wonder whose phone is on the table.)

• Note about relative clauses: który is also the standard relative pronoun ("which/that") used to connect clauses: Dom, który kupiliśmy, jest stary. That is not a question — it’s a relative clause. czyj is normally not used as the relative pronoun for "whose"; for relative possession Polish usually uses którego (or other relative forms), e.g. Mężczyzna, którego syn znam...

Important rule about case in subordinate clauses
The case of który or czyj is determined by the role the pronoun (or the noun it modifies) plays in the subordinate clause. In other words, ask "who? whom? to whom? about whom? with whom?" inside the subordinate clause, and put the pronoun into the corresponding case.

Examples that show this rule (each subordinate clause is underlined conceptually):

• Subject (nominative): Nie wiem, który pociąg odjeżdża o 10. (I don't know which train leaves at 10.)


• Direct object (accusative): Nie wiem, którą książkę wybrał. (I don't know which book he chose.)


• Genitive required by verb (genitive): Nie pamiętam, którego domu szukasz. (I don't remember which house you are looking for.) — verb szukać often governs genitive.


• After preposition (locative or instrumental): Zastanawiam się, o którym filmie mówili. (I wonder which film they spoke about.) / Nie wiem, z którym kolegą idziesz. (I don't know which colleague you're going with.)


• Possession (czyj in nominative): Nie wiem, czyj to jest rower. (I don't know whose this bicycle is.)


• Possession after preposition: Zapytaj, z czyim samochodem przyjechał. (Ask whose car he arrived in.) — preposition z + instrumental.

Direct vs indirect word order]
Polish indirect (embedded) questions usually keep normal (declarative) word order; you do not have to put the verb before the subject as in some direct questions. Compare:

• Direct: Który film oglądasz?


• Indirect: Powiedz mi, który film oglądasz.

Common confusions and mistakes

• Using the case required by the main clause instead of the subordinate clause. Wrong: *Nie wiem, który zobaczyłeś ją. (You must make który agree with its role inside the subordinate clause.)


• Mixing up czy and czyj. czy introduces yes/no questions (whether); czyj asks "whose". Compare: Nie wiem, czy przyjdzie (I don't know whether he will come) vs Nie wiem, czyj to jest pies (I don't know whose dog this is).


• Confusing który and jaki. który = which (choice among options). jaki = what kind / what sort of (asking for description). Example: Powiedz mi, który film wybrałeś (Which one did you choose?) vs Powiedz mi, jaki to był film (Tell me what kind of film it was).


• Trying to use czyj as a relative pronoun for possession in contexts where Polish prefers a relative form of który (e.g. use którego in many relative phrases): Mężczyzna, którego syn znam (the man whose son I know) — not *Mężczyzna, czyjego syn znam.

Quick tips / cheat sheet

• Decide what question word you would use inside the subordinate clause (kto? kogo? komu? o kim? z kim? czyj?). That tells you the case.


• Use the form of który or czyj that matches the noun (gender/number) and the case required by the subordinate clause.


• Use który z ... for "which of ..." (e.g. który z tych filmów).

Examples (Polish — English translation) — short annotated list

• Nie wiem, który pociąg odjeżdża o 10. — (I don’t know which train leaves at 10.)


• Nie wiem, którą książkę wybrał. — (I don’t know which book he chose.)


• Nie wiem, którego domu szukasz. — (I don’t know which house you’re looking for.)


• Powiedz mi, o którym filmie mówili. — (Tell me which film they talked about.)


• Nie wiem, z którym kolegą idziesz. — (I don’t know which colleague you’re going with.)


• Nie wiem, czyj to jest rower. — (I don’t know whose bike this is.)


• Nie wiem, czyje są te okulary. — (I don’t know whose glasses these are.)


• Nie wiem, czyim samochodem przyjechał. — (I don’t know in whose car he arrived.)


• Powiedz mi, który z tych dwóch wygraliśmy. — (Tell me which of these two we won.) ["który z" = which of]


• Direct vs indirect:


• Direct: Który film oglądasz?


• Indirect: Powiedz mi, który film oglądasz.

Common patterns to remember

• "Which" among options = który (often with z — który z…).


• "Whose" = czyj (declines like an adjective/possessive).


• The pronoun’s case is decided inside the subordinate clause, not by the main clause.

Short glossary

• Subordinate clause: a clause that depends on a main clause (e.g. "I don’t know ").


• Interrogative pronoun: a pronoun that asks a question (który, kto, co, czyj, jaki ...).


• Relative pronoun: a word that links two clauses and refers back to a noun (in Polish often który means "which/that").


• Agreement: the pronoun must match the noun it refers to in gender, number and case.


• Case: grammatical form showing role in clause (nominative, genitive, dative, accusative, instrumental, locative).

Final tip
When in doubt: form the subordinate clause as a stand-alone question (mentally) and ask the appropriate "who/what/whose/whom/with whom/about whom" question. Then put który or czyj into the case that that question requires, and make it agree with the noun in gender/number.