What are some examples of their usage? Is なん the short form of 何【なに】 in both words?
Also, not sure if this is correct, but the だ in the middle of なんだか should be the copula. Why is the copula being used like this in the middle of a word?
Japanese Language Stack Exchange is a question and answer site for students, teachers, and linguists wanting to discuss the finer points of the Japanese language. It only takes a minute to sign up.Sign up to join this community
Although だ should be etymologically the copula, but as you can see in the link, it would be simpler to consider them as independent words on their own.
なんだか is three words なん + だ + か but it's become a set phrase and is used as a word itself pretty much to express an idea like somehow, somewhat, or rather.
It's rather cold today.
なんか is different with a couple of different uses. It's usually an informal version of なにか or など.
I want something cold to drink.
I have no interest in things like painting and music.