~더라 is an ending form relating what one has already experienced first hand, so can only be about the past. -더라고(요) makes it sound like the phrase is still continuing - it adds fluidity. Most -고 at the end has this function. "아버지는 돈이 없다고 하더라고요." => You know, dad was saying he's broke. Examples: - 미스터 김 알지? 어제 보니까 큰 차를 샀더라고. => You know Mr Kim, don't you? I saw him yesterday. He bought a big car. - 그 집 가봤는데 형편이 안 좋더라고. => I visited that family. They're in bad shape financially.

~더라고(요) is used when you talk about something you've learned by your own experience or from someone else or some other things (e.g. books, TV and internet). ex) 급하게 어디를 가더라고요 = (He was) going somewhere in a hurry 기린은 목이 길더라고요 = (I learned that) a giraffe has a long neck. 큰 배가 항구를 향해 오더라고요 = (I learned/saw that) a big ship was coming towards the port 그렇게 생각하니까 편해지더라고요 = (I learned that) I became (more) relaxed as I think that way -다고 하더라고요 means "(I heard that) someone said that ..." 아버지는 돈이 없다고 하더라고요. (I heard that) my father said, "I don't have money". =(I heard that) my father said that he did have money.