" 안녕하세요 virtuonweb 입니다 "
이번 글에서는 언니, 오빠, "~씨" 에 대해 알아볼까 한다.
I know new Korean learners are sometimes taught to use -씨 when referring names.
They are also taught not to call anyone 언니/오빠/선배 unless the older person specifically says that we can. If we do call them that without permission then it’s considered rude. This because foreigners don't want people they are speaking with to think “we’re not that close, why is she calling me this”.
However, this isn't true in real life, and it's never that rude to call 언니/오빠.
First of all, (누구)씨 is the "most" polite way to call someone. Like when you first meet your boyfriend's friend or sth. You barely knew her name and like basically her name is all you know about her. But after several conversations, you can just switch off to calling him 언니 or 형(if male to male). At least this is what I do as a Korean when I first get to know a person.
In my perspective I think (누구) is usually used exclusively among people 30+,40+ years old. Younger generations get along with each other easily and say 형/누나/언니/or by names if you are talking to a younger person. As you know, it's more friendly and casual(but not rude)
I've thought about instances when I was called as OO씨. And there was only one case. It was when a 형 6 years older than me called me like that in a class where I first met him. I was uncomfortable being called like it and said "형 편하게 말씀하세요"(since he was deliberately calling me OO씨 even though he could just call me OO아, to show respect). Then he said "OO씨도 편하게 말씀하시면 그렇게 할게요."(referring me to speak in 반말). But I am not used to speak 반말 to people 6 years older than me, so I said "저는 존댓말 할테니 형은 편하게 말하세요 ㅎㅎ" -> Usually after this elder people say okay and speaks in 반말 but he didn't. I think he was really polite.
Besides, I don't think I've heard OO씨 before. We speak in 존댓말 at first and whoever feels uncomfortable first says "아 편하게 말씀하세요", and then we begin speaking in 반말. (When speaking in 존댓말, you can kinda prevent yourself from calling the 호칭 by deleting pronouns in the sentence).
To sound rude it's more about 반말/존댓말 than the 호칭.
Feel free to ask any questions!