온 줄

thought that … had come

→ 오다
phrase Common #3,635
thought that … had come Usually appears with 알다 (to know/think) or 모르다 (not to know/realize). The tense and meaning of the full phrase depend on the verb form before 줄.
KO: 네가 이미 온 줄 알았어.
EN: I thought you had already come.