When we want to quote someone or reference something that you heard/said/read/etc or a fact that you know, then you have to conjugate the verb a special way in Korean, by using (이)라는,(이)라고 for nouns, and (ㄴ/는)다는,(ㄴ/는)다고 for verbs.
N + (이)라고 하다
N + (이)라고 + 말하다/듣다/읽다/쓰다
N + (이)래요
1. To say that a noun is called something, you use you use N + (이)라고 하다.
If it’s something that you heard/said/read/etc, you attach those verbs too.
N + (이)래요 is the short form for (이)라고 해요.
뭐라고 했어요? – What did you say?
그 사람이 성생님이라고 들었어요. – I heard that this person is a teacher.
N1 + (이)라는 + N2
N1 + (이)란 + N2
2. You use N1 + (이)라는 + N2 when you want to reference a noun which is called another noun.
This is equivalent to saying, a N who is N.
N1 + (이)란 + N2 is the short form.
성생님이라는 사람 – This person who is a teacher
V + (ㄴ/는)다고 하다
V + (ㄴ/는)다고 + 말하다/듣다/읽다/쓰다
V + (ㄴ/는)대요
3. To say that V happened, but you know it indirectly, you use V + (ㄴ/는)다고 하다.
If it’s something that you heard/said/read/etc, you attach those verbs too.
V + (ㄴ/는)대요 is the short form for (ㄴ/는)다고 해요.
뭐라고 했어요? – What did you say?
그 사람이 내일 온다고 해요. – He said he will come tomorrow.
이거 재미있다고 들었어요. – I heard that this is fun.
V + (ㄴ/는)다는 + N
V + (ㄴ/는)단 + N
4. You use V + 다는 + N when you want to reference a noun which has an indirect verb as an adjective modifying it.
This is equivalent to saying, a N which is / who is doing V.
V + 단 + N is the short form.
한국에 간다는 사람 – A person who is going to Korea.
나는 그녀가 도착했다는 것 알아요. – I know the fact that she had arrived.
V + (으)라고 하다
V + (으)래요
5. You use V + (으)라고 하다 when you are quoting an imperative statement.
V + 래요 is the short form.
그 사람한테 하지말라고 했어요! – I told him to stop doing it!
V + 자고 하다
V + 재요
6. You use V + 자고 하다 when you are quoting an suggestive statement.
V + 래요 is the short form.
친구랑 집앞에서 만나자고 말했어요 – I told to meet my friend in front of the house.
V + 냐고 하다
V + 냬요
7. You use V + 냐고 하다 when you are quoting an interrogative question.
V + 냬요 is the short form.
그 놈은 잘 지내냐고 말했어요 – That guy asked me how I was doing.
V + 더라고 하다
8. You use 더라고 하다 when you are quoting something that you saw directly or experienced first hand.
사람이 진짜 많더라고요! – There was a lot of people there! (I saw with my eyes)