What are the differences between какой and что?
I know that when used in interrogation, какой can mean either "what" or "which", but, when both of them mean "what", what are the differences between them??
In russian - it's not big different, it's a two different words, even not synonymous.
Какой - it's the question of quality properties. Какой сегодня день? - What day is today? Какая сегодня погода? - What is the weather today?
Что - it's interrogative or union word is used in the formulation of the general question of the object, phenomenon, action in matters of inanimate subjects. Что случилось? - What happened? Я знаю, что он уже был там. - I know that he was there. Мы видим, что за этим кроется. - We see what lies behind it. Что сто́ит? - How much is?
Very good answer (I suspect you are Russian :D tell me if you are so that your answer will be more trustable for me пожалуйста!!) Очень спасибо!!
Yes, I'm Russian :)
One more point: not say "Очень спасибо", say "Большое спасибо"/"Big thanks" (99%), or "Очень благодарен"/"very grateful" (more literary, rare in speech).
Basically какой is a replacement for an adjective (Какой цвет? Красный цвет! - What colour? Red colour!), and что is a replacement for a noun (Что я вижу? Я вижу кошку. - What do I see? I see a cat.)
Какой is an adjective, so it's meaning is more along the lines of "what kind of" rather than simply "what".
No, it is not. It is a pronoun. It can function as an adjective, conjunction, question and something else.
But in the context of the original question, I guess, we can really just see if the answer is an adjective, then "what" becomes "какой", if not, then it is "что".
When you ask "Какой" - you ask about property of something. Какой кот? - кот большой. What cat. Cat is big "Which" usually means 'Который' (which one). "I like the cat. Which one? This black one. " - Мне нравится кот. Который? Вот этот черный.