그 책을 읽다 보니 재미있더라고요. While reading the book, I learned that it was interesting. ~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). Replace 다 of a plain form of verbs/adjectives with 더라고. 하다 → 하더라고 = (learned that someone) was doing Example sentence: 진수는 음악을 전공 하더라고 = I learned that Jinsu was doing a major in music 가더라고 = (I learned that) was going 오더라고 = (I learned that) was coming 먹더라고 = (I learned that) was eating 마시더라고 = (I learned that) was drinking 살더라고 = (I learned that) was living 만들더라고 = (I learned that) was making 일하더라고 = (I learned that) was working 자더라고 = (I learned that) was sleeping 높더라고 = (I learned that) was high 낮더라고 = (I learned that) was low 크더라고 = (I learned that) was big/large 작더라고 = (I learned that) was small (in size) 빠르더라고 = (I learned that) was fast 느리더라고 = (I learned that) was slow 많더라고 = (I learned that) was many 적더라고 = (I learned that) was small (in quantity) Attach 요 to 더라고 to make it a polite form. 하더라고요 (Polite spoken form) 가더라고요 많더라고요 크더라고요 Example sentences: 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

Not very much, but it means anyway you find something out personally and directly. You know that book is interesting, not because somebody told you, but because you have read it.