The usage of 다면서/라면서 and 다고/라고

~다면서? is used with verbs, ~라면서? is used with nouns. Both means "I heard you are ~" so it's basically you are guessing something about someone did something or is something. Let's try some examples. Let's say I met you and I'd like to say "I heard you are good at Korean" It could go like "칠성님! 한국어를 잘 한다면서요?" 한국어를 잘 하다 is the original and you add 다면서요 next to it. You can make past and future tense as well. Another one can be; I heard you already ate -> 너 이미 밥을 먹었다면서? 이미 is already and 밥을 먹었다 is past tense. And you can add 다면서 to it. 라면서 is just the same but used with nouns. But in this case there is two kinds of it. ~이라면서 / ~라면서. You might already know the different usage of 을/를. When 을 is next to the letter with final consonant, 를 comes without one. Same in that context. 이라면서 goes with nouns with final consonant at the end, while 라면서 goes with the one without final consonant. Let's give an example. I heard your wife is a police? -> 네 아내가 경찰관이라면서? But let's change police to a nurse. -> 네 아내가 간호사라면서? See the difference? 🙂

If you are asking what is the difference between group A "다면서/라면서" and group B "다고/라고" then you already know what the first ones mean, 다고/라고 means similar but kind of different. Group A is like, there's no context before and usually you are the one who start the subject. Like as the examples, asking and confirming what you already know " I heard (something) is (something), right?" Group B is used differently. You usually hear something you did not know befofe. Like, let's say you heard one of your friend is pregnant. Then you'd be like "what? You are pregnant?" In this context, you did not know your friend was preg before but now you know and asking if you heard it right. So it goes like: "뭐? 너 임신했다고?" 임신하다 is being pregnant so make it past tense. If you ask the difference between 다고 and 라고, you can guess. Yes, the rule I mentioned before with verbs and nouns applied same here. 다고 is with verbs and 라고 is with nouns. Then again, you will know the difference between 라고 and 이라고.