idk if your misc thread is the kind of thread that's allowed. i think it's suited for the questions thread, but...
i don't speak korean (but i'm also trying to learn), but if i recall correctly, korean and japanese sentence structure and grammar are very similar as they are both agglunative languages. if i recall correctly, the also share a lot of similar phonetics. a difference between the two's grammar that i know of is the fact that japanese only has 2 irregular verbs, whilst korean has more than that (but i'm not sure how many)
also, the written korean language is a lot more simple. there are 14 base letters that change depending on the lines you add to them (but they are minor changes; like if you add a line to the letter giyeok (a g/k noise) it becomes kieuk (a stonger g/k noise, with an aspirated breath of air)) and you combine those letters to make letter blocks, which are all a syllable.
i don't know if that helps you, i hope it does.