계속 and 계속해서 Any difference in meaning follows their function in the sentence. When they describe the manner of something continuing, they are completely interchangeable. In such usages, 계속 is simply a short form of 계속해서, so there is no difference at all. - 비가 이틀을 계속/계속해서 내렸다. => It's been raining continually for two days. - 계속/계속해서 같은 말만 하고 있다. => (He) keeps saying the same thing. - 사업에 계속/계속해서 실패했다. => (He) kept failing in his business. Sometimes, ~해서 in 계속해서 means a reason or background. In this case it can't be shortened to 계속. In such usages, 계속해서 is equivalent to 계속한 끝에, 계속했기 때문에, or 계속하다 보니까, etc. - 실패를 계속해서 가세가 기울었다. (The subject 가세가 separates 기울었다 from 계속해서) => After a string of failures, the family fortune declined. - 공사를 계속해서 시끄럽다. (Structurally, it is [공사를 계속해서] 시끄럽다. "공사를 [게속해서 시끄럽다]" makes no sense) => Continuing construction work makes it noisy. All the above examples are their adverbial usages, but 계속 is sometimes used as a noun too. - 이번 회는 지난 주 이야기의 계속이다. (This episode is a continuation of last week's story)