[Tehnix]

>I'm guessing that for Korean it's mostly the grammar differences, honorifics

Definitely! And some other differences too. As someone living in South Korea currently, the reading/writing part is trivial, but beyond that it is a lot harder to learn (for an english speaker (although I'm danish)) than, say, French.

I definitely disagree that Korean and Spanish would be considered equally hard, and know literally no one here that would say that either.

[gpetukhov]

Maybe that person is the speaker of Arabic. For them, Korean and Spanish should be equally distant.