What does "신기하네... 그럼 무슨 뜻일까 ㅋㅋ 안에... 철처럼 딱딱핰 한가요" mean and how do I respond?
I mentioned to my Korean cousin in a group chat that I was learning Korean but understood some things. Her friend messaged back "신기하네... 그럼 무슨 뜻일까 ㅋㅋ 안에... 철처럼 딱딱핰 한가요". I'm guessing there's some bits of it that are slang.

From my limited knowledge (I'm still learning!) I gather it's something about "what does this mean" and I think one bit means "bullshit". It'd be really helpful if someone could translate for me. And maybe give me a way to respond to it as well, either in English or Korean! It'll help me learn some (I think?) slang and help me communicate. Thanks!

Question

What does "신기하네... 그럼 무슨 뜻일까 ㅋㅋ 안에... 철처럼 딱딱핰 한가요﻿" mean and how do I respond?
I mentioned to my Korean cousin in a group chat that I was learning Korean but understood some things. Her friend messaged back "신기하네... 그럼 무슨 뜻일까 ㅋㅋ 안에... 철처럼 딱딱핰 한가요﻿". I'm guessing there's some bits of it that are slang.

From my limited knowledge (I'm still learning!) I gather it's something about "what does this mean" and I think one bit means "bullshit". It'd be really helpful if someone could translate for me. And maybe give me a way to respond to it as well, either in English or Korean! It'll help me learn some (I think?) slang and help me communicate. Thanks!

Answer

"신기하네... 그럼 무슨 뜻일까 ㅋㅋ 안에... 철처럼 딱딱핰 한가요"  (딱딱핰 한가요 -> 딱딱한가요)

- 신기하네 - It's curious/fascinating.
- 그럼(then) What(무슨) 뜻(meaning)일까(is it?) => What does it mean then? 
- 안(inside)에(in, at) => inside.
- 철(iron)처럼(like) 딱딱한(hard)가요(is it)? => Is it hard like iron?

So it is: "How curious.  What could that mean? Lol. Is it hard like steel ... inside?"

The sentence sounds like it is referring to something unrelated to your learning Korean.

Ne manquez pas cette occasion d'apprendre une langue depuis chez vous. Découvrez notre sélection de professeurs de langues expérimentés et inscrivez-vous dès maintenant à votre premier cours !