What is the difference between using который or какой?

Question

It seems like they both mean "which." I know the combination of такой (же)…какой implies similarity, so is that the basic difference? In other words, does using какой over который in a sentence imply some sort of similarity in the things being discussed?

Answer 1

Который  is a pronoun, that can be used to connect clauses within sentences. We can say that it means "which one" and it is assumed that there is a list of possibilities:

Фильм, который мне понравился больше всего, вышел на DVD.

Люди, которые работают в офисе, обедают там же.

Который is also used as an interrogative pronoun if followed by из or other prepositions (Которая из этих книг тебе больше понравилась?) , but I personally wouldn’t say we use it in questions a lot. In this case it is much more natural to substitute it with Какой (Какая из этих книг тебе больше понравилась?)

Какой is also an interrogative pronoun, which is frequently used in everyday speech. It can also connect clauses within a sentence:

Я не знаю, в какой день приеду обратно.

Я радуюсь тому, какие подарки приносят дети.



Answer 2

Который = which one

Какой = what kind of

Answer 3

Какой is really the question to ask - "which, or what kind?", the word который, on the other hand is used as a substitute for a noun when joining two clauses into a full sentence. They are really separate concepts.

Example:

Какие книги вы читаете? (Which books are you reading?)

Я читаю книги, которые хорошие. (I am reading the books, which are good.)

Я читаю книги, о которых вы мне сказали. ( I am reading the books, about which you told me.)

Который follows the gender and declension for whatever it is refering to (in that last case, the plural books.)