I have no problems in spelling, maybe because I learned them from English textbooks.
But I totally have no control over what I say. The things I say may have a sprinkle of Korean words, so when I greet people it's like all of a sudden I'm all "Annyong Annyong!~". Or when something irritates me, I go "Aiguuuuuuuu!", and when I'm angry and want to get a point across, an "Arachi!!" slides off my mouth. I'm not exactly sure if I'm getting it right.

I'm wondering if I'm just watching a bit too much non-subbed Korean movies.