English "what" and "which" overlap so much that most speakers never feel a difference. Polish keeps them apart with two distinct words, jaki and który, and the difference is real: one asks what something is like, the other asks which specific one you mean. Choose wrong and you change the question — from describing a thing to picking it out of a lineup.
The core distinction in one sentence
Use jaki to ask about quality or type ("what is it like / what kind of"); use który to select one item from a known, limited set ("which one of these").
The decision rule
Ask yourself what answer you expect:
- If the answer is a description or a category (a colour, a quality, a type — "red", "Japanese", "big") → jaki.
- If the answer is a choice from defined options (this one, the third one, the one on the left) → który.
Both words decline like adjectives, agreeing in gender, number and case with their noun: jaki / jaka / jakie, który / która / które.
jaki: asking about quality and type
Jaki opens an open-ended question about the nature of something. There is no fixed list to choose from; you want a description back.
Jaki masz samochód?
What (kind of) car do you have?
Jaka jest dziś pogoda?
What's the weather like today?
Jaki to był film? Komedia czy dramat?
What sort of film was it? A comedy or a drama?
The expected answers describe or classify: I have a small red Toyota; it's cold and rainy; it was a comedy. Notice Jaki to był film? literally asks "what kind of thing was that film?" — you are after its genre, not its identity.
Jaki also serves as an exclamation of degree, like English "what a…!":
Jaki piękny widok!
What a beautiful view!
który: selecting from a known set
Który assumes a bounded set already in play and asks you to single out a member of it. The expected answer points: this one, that one, the second one.
Który samochód wybierasz — czerwony czy niebieski?
Which car are you choosing — the red one or the blue one?
Którą sukienkę kupić, tę czy tamtą?
Which dress should I buy, this one or that one?
Na którym piętrze mieszkasz?
Which floor do you live on?
The set can be explicit (two cars in front of you) or merely understood (the floors of a building, the days of the week). What matters is that you are picking out one of several, not describing.
Który is also the everyday word for ordinal-type "which number" questions:
Która godzina?
What time is it? (lit. which hour)
The genuinely ambiguous cases
This is where the choice does real work, because English hides it. Take "what colour do you want?" — Polish forces you to decide what you're really asking:
Jaki kolor chcesz?
What colour do you want? (open — describe any colour you like)
Który kolor chcesz?
Which colour do you want? (selecting — from the colours available here)
Jaki kolor? invites a free answer ("blue, maybe turquoise"). Który kolor? assumes a palette in front of you and asks you to point at one. Both are correct Polish; they simply ask different questions. A shop assistant gesturing at three paint samples uses który; a friend with no constraints asks jaki.
The same fork appears with restaurants, books, routes:
Jaką muzykę lubisz?
What (kind of) music do you like? (open — describe your taste)
Którą piosenkę puścić?
Which song should I play? (selecting — from the ones available)
który as a relative pronoun
Beyond questions, który is also the main relative pronoun, "who / which / that", linking a clause to a noun. Jaki can occasionally do this too, but with a "of the kind that" flavour. For everyday relative clauses, który is the default.
To jest człowiek, którego widziałem wczoraj.
This is the man (whom) I saw yesterday.
Szukam mieszkania, które ma balkon.
I'm looking for a flat that has a balcony.
When jaki appears as a relative, it shifts the meaning toward "the kind of … that": takie mieszkanie, jakie chcę ("the kind of flat that I want"). This pairs naturally with taki ("such / that kind"). For the full relative paradigm see the relative który page.
A sorting drill
| English | What you want back | Polish |
|---|---|---|
| What's your new flat like? | a description | Jakie jest twoje nowe mieszkanie? |
| Which flat did you rent? | one of the ones you saw | Które mieszkanie wynajęłaś? |
| What languages do you speak? | a list / type | Jakimi językami mówisz? |
| Which of these languages is easiest? | pick from the set | Który z tych języków jest najłatwiejszy? |
| What kind of person is she? | character description | Jaka ona jest? |
| Which woman do you mean? | identify one | Którą kobietę masz na myśli? |
Source-language comparison
English "what" and "which" can mark this distinction — "what car" (type) vs. "which car" (selection) — but in casual speech the two blur, and many speakers use "what" for both. Polish does not allow the blur: you must commit to describing (jaki) or selecting (który) every time. The practical consequence for English speakers is that questions feeling identical in English ("what colour / which colour") split in Polish, and picking the wrong one mildly miscommunicates — you sound as if you're describing when you meant to choose, or vice versa. A second snag: English uses "which" as a relative ("the flat which has a balcony"), and Polish matches this with który, so the relative use feels familiar — but resist carrying jaki into ordinary relative clauses. For the determiner family including czyj ("whose"), see the który/jaki/czyj page.
Common Mistakes
❌ Który masz samochód?
Incorrect if you mean 'what kind' — który implies choosing from specific cars present.
✅ Jaki masz samochód?
What (kind of) car do you have?
❌ Jaką sukienkę kupić — tę czy tamtą?
Incorrect — choosing between two named options needs który/którą.
✅ Którą sukienkę kupić — tę czy tamtą?
Which dress should I buy — this one or that one?
❌ Jaka jest godzina?
Unidiomatic for telling the time — Polish fixes this as która godzina.
✅ Która godzina?
What time is it?
❌ To jest film, jaki widziałem wczoraj.
Incorrect for a plain relative — use który here, not jaki.
✅ To jest film, który widziałem wczoraj.
This is the film (that) I saw yesterday.
❌ Który jest dziś dzień?
Unidiomatic — to ask the day of the week, Polish prefers jaki.
✅ Jaki jest dziś dzień?
What day is it today?
Key Takeaways
- jaki asks about quality / type — the answer describes or classifies (a colour, a quality, a genre).
- który asks you to select from a known set — the answer points to one option.
- When English hides the choice ("what colour"), decide whether you want a description (jaki) or a pick from options (który).
- który is also the everyday relative pronoun ("the man whom…"); save relative jaki for "the kind that", usually after taki.
- Fixed idioms: Która godzina? (the time), Jaki jest dziś dzień? (the day) — learn these as set phrases.
Now practice Polish
Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.
Start learning Polish→Related Topics
- which, what kind, whose: który, jaki, czyjB1 — How Polish splits English 'what/which' into który (selecting from a set) and jaki (asking about quality or kind), plus the dedicated possessive question word czyj ('whose').
- 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.