when your profesor is a little bit confused :)
So, what's the difference in meaning between "di mana" and "di manakah"? I don't know what the "-kah" is doing there yet.
it's only diction.. like in books in elementary education or poem, etc. for conversation, just use "dimana"..
ex : dimana kamu tinggal? (formal) /
kamu tinggal dimana? (informal).
I think it's a Japanese-ism...?
To denote any question in Japanese, you add "kah?" at the end. Though it's some distance away I think Japan has some cultural influence in Indonesia...