19 CommentsThis discussion is locked.
"정말" and "진자" mean "really" in English. In my opinion, the latter is more popular than the former. Also, these words are written informally. If you're talking to someone who's older than you or superior to you (i.e. a boss), you need to use and "정말요" or "진자요" regardless of whether they're used in interrogative or declarative forms.