계속 means "continuously, consecutively, (formal) unceasingly" 눈이 10일 동안 계속 내렸다 It snowed for ten consecutive days. 우리는 계속 적자를 내고 있다 We are constantly in deficit[the red]. 이번 주말까지는 계속 바쁘다 I will be busy till[to] the end of the week. 자꾸 means "repeatedly, again and again, over and over again, frequently" 문을 자꾸 두드리다 knock repeatedly on the door 자꾸 실수하다 keep making mistakes 그가 요즘 자꾸 당신 이야기를 해요 He often[frequently] talks about you these days.