English uses "what" and "which" loosely — "what film did you see?", "which film did you see?" feel almost interchangeable. Polish refuses to blur them. Który asks you to select one item from a known set ("which one of these?"); jaki asks about quality or kind ("what sort of thing is it / what is it like?"). On top of that, Polish has a dedicated declining word for "whose" — czyj — where English just bolts "-'s" onto a name. All three agree with their noun in gender, number and case and decline like adjectives. Getting który vs jaki right is the difference between sounding fluent and sounding translated.
który — selection from a set
Use który when you are choosing among specific, identifiable options. The set may be visible ("which of these cars?") or simply known to both speakers ("which train — the one at 9 or the one at 10?"). The English clue is usually "which", and you could often answer by pointing.
Który samochód jest twój — ten czerwony czy ten niebieski?
Which car is yours — the red one or the blue one?
Który pociąg wybierasz, ten o dziewiątej czy o dziesiątej?
Which train are you choosing, the nine o'clock or the ten o'clock?
W którym pokoju śpią dzieci?
Which room do the children sleep in?
Który is also the main relative pronoun ("the man who...", "the book which..."), but that use is covered separately — see relative który. Here we focus on its question-word, selecting role.
jaki — quality, kind, what something is like
Use jaki when you are asking about the nature of something — its kind, its qualities, its appearance — not about picking one item from a list. The English clue is "what kind of", "what ... like", or a bare "what" where you expect a description rather than a name.
Jaki masz samochód?
What car do you have? (make, type, colour…)
Jaka jest pogoda w Krakowie?
What's the weather like in Kraków?
Jaki on jest — miły czy raczej zamknięty?
What's he like — nice, or rather reserved?
Notice the answers these expect: not "this one" but "a red Toyota", "sunny", "very kind". That is the test. If a natural answer is a description, use jaki. If a natural answer is "that one", use który.
The classic minimal pair
Put them side by side and the difference is sharp:
| Question | Polish | What you're asking |
|---|---|---|
| Which film are you choosing? | Który film wybierasz? | pick one from a set |
| What kind of film is it? | Jaki to film? | genre / quality |
| Which colour do you want? | Który kolor chcesz? | pick from available colours |
| What colour is it? | Jakiego koloru jest? | describe its colour |
That last row is worth memorising. "What colour is it?" is Jakiego koloru? — jaki in the genitive, because colour is a quality, not a choice from a menu. Saying Który kolor jest? for "what colour is it?" is a textbook error.
Jakiego koloru jest twój nowy płaszcz?
What colour is your new coat?
Który kolor wybierasz na ściany — beżowy czy szary?
Which colour are you choosing for the walls — beige or grey?
czyj — whose
Czyj asks about possession. English has no declining "whose"-word that changes shape; Polish does, and it agrees with the thing possessed, not the possessor. So "whose car?" is czyj samochód? (masculine, agreeing with samochód), "whose book?" is czyja książka? (feminine), "whose child?" is czyje dziecko? (neuter).
Czyj to samochód stoi przed bramą?
Whose car is that parked in front of the gate?
Czyja jest ta torba? Ktoś ją tu zostawił.
Whose is this bag? Someone left it here.
Czyje są te buty w przedpokoju?
Whose are these shoes in the hallway?
They all decline
Like other determiners, all three inflect for case along with the noun they question. The endings are adjectival.
| Case (masc. sg) | który | jaki | czyj |
|---|---|---|---|
| Nominative | który | jaki | czyj |
| Genitive | którego | jakiego | czyjego |
| Dative | któremu | jakiemu | czyjemu |
| Accusative | którego / który | jakiego / jaki | czyjego / czyj |
| Instrumental | którym | jakim | czyim |
| Locative | którym | jakim | czyim |
O którym filmie mówisz?
Which film are you talking about?
Z czyjego konta przyszedł ten przelew?
Whose account did this transfer come from?
A note on ile — how many / how much
Alongside this group sits ile ("how many / how much"). Like the vague quantity words, it governs the genitive: Ile masz czasu? ("How much time do you have?", genitive czasu), Ile osób przyjdzie? ("How many people will come?", genitive plural osób). It is covered with the quantity words rather than here, but it is the natural partner of który/jaki in the question family.
Ile masz lat?
How old are you? (lit. how many years do you have?)
Common Mistakes
❌ Który masz samochód?
Incorrect for asking about make/type — that's a quality, so use jaki
✅ Jaki masz samochód?
What (kind of) car do you have?
❌ Jaki film wybierasz, ten czy tamten?
Incorrect — choosing one from two is selection, so use który
✅ Który film wybierasz, ten czy tamten?
Which film are you choosing, this one or that one?
❌ Który kolor jest twoja sukienka?
Incorrect — 'what colour is it' is a quality: jakiego koloru
✅ Jakiego koloru jest twoja sukienka?
What colour is your dress?
❌ Kogo to jest samochód?
Incorrect — 'whose' has its own word; don't use the genitive of 'who'
✅ Czyj to jest samochód?
Whose car is this?
❌ Czyj jest ta książka?
Incorrect — czyj must agree with książka (feminine): czyja
✅ Czyja jest ta książka?
Whose is this book?
Key Takeaways
- który = selection from a known set ("which one?"); you could answer by pointing. It is also the relative pronoun "who/which".
- jaki = quality or kind ("what ... like / what sort?"); you answer with a description. "What colour is it?" = jakiego koloru?
- czyj = "whose", a dedicated declining word that agrees with the thing possessed (czyj samochód, czyja książka, czyje dziecko) — don't substitute the genitive of kto.
- All three decline like adjectives and agree with their noun; for the fuller selection-vs-description discussion see jaki vs który.
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- Relative Pronouns: który, jaki, coB1 — który joins clauses by taking its gender and number from the noun it refers to but its case from its own job inside the relative clause — plus the obligatory comma and the alternatives jaki and co.
- Question Words: kto, co, gdzie, kiedy, dlaczego, jakA1 — How Polish wh-questions work: the question word goes first, the rest keeps statement order, there's no 'do' auxiliary, intonation falls — and kto/co/który must appear in the exact case their role in the sentence demands.
- Determiners: OverviewA2 — A survey of Polish determiners — demonstratives, possessives, quantifiers and question words — which agree with their noun and, unlike English articles, are optional rather than obligatory.
- jaki vs który: What Kind vs Which OneB1 — How to choose between jaki (asking about quality or type) and który (selecting one item from a known set).
- Interrogative Pronouns: kto, coA1 — The question words kto 'who' and co 'what' fully decline — the case you choose telegraphs how the answer fits into the sentence, and kto always triggers masculine agreement.