Basically there are four ways to use 당신. And you’d better pay attention here — especially to the first usage.
1. Using 당신 when you want to start a fight.
2. Using 당신 with your husband or wife.
3. Using 당신 when the listener or audience is not a specific person.
4. Using 당신 to mean “he” or “she”. (Actually, it’s hardly ever used this way.)
1. Use 당신 when you want to start a fight.
당신 as a very rude way of calling somebody “you”. But 당신 is extraordinarily blunt and informal, and its usage in Korean is so restricted that if you don’t use it correctly you’re going to end up starting a fight. In fact, 당신 is used to belittle and provoke someone. If you’re arguing with someone in Korean — yelling and screaming — at least the fight hasn’t escalated into physical confrontation. But if you start referring to that person with the pronoun 당신, that’s the equivalent of poking them in the chest. Now you’ve gone physical. Now we’re talking fisticuffs. That’s right. I used the word ‘fisticuffs’.
Because 당신 means “you” in such a very blunt and informal way, there’s pretty much no one you could possibly use 당신 with in civil conversation. Except perhaps your husband or wife; someone with whom you’re extremely close and/or intimate. No, you can’t use it with your girlfriend. (Unless you want to fight them. See usage #1.) No, you can’t use it with your best friend. (Unless you want to fight them. See usage #1.) No, you can’t use it with a subordinate at work. (Unless you want to fight them. See usage #1.) Have I made it clear yet that 당신 almost always sounds like you’re starting a fight? Good. If you’re 100% positive that you understand this point, then it’s safe to tell you that you’re also allowed to use 당신 with your husband or wife, as long as they’re cool with that. If not, you’ll know. How? Fisticuffs.
I think it’s worth pointing out that using 당신 (“you”) with your husband or wife is not something that younger couples typically do. It’s mostly middle-aged and older couples. There’s nothing wrong with using 당신 if you’re a young couple. It’s just not normal. It’s like hearing a 50 year old couple calling each other “자기” (instead of “여보”). Or like getting a text from a 40 year old woman who still uses phrases like “넹넹”. It’s just kinda’ weird.
Let’s take a question from the audience.
“But I hear 당신 all the time when I’m watching Korean dramas. So it must be okay to use, right?”
Yes. You’ll hear 당신 an awful lot when you’re watching Korean Dramas. BUT… it’s almost always used in one of the two usages above. Go back and watch your drama. 9 times out of 10, the word 당신 is being used right before a fight or during one. And even when it’s being used between husband and wife, it’s usually during an argument that you’ll hear it. Understand?
“Wait a minute! I hear 당신 in other places besides dramas. I hear it in songs; I see it in advertisements; I see it when I walk into TGIFriday’s. What the hell? I’m pretty sure it’s okay to use 당신 a bit more frequently than, umm…. errr…. never.”
Yep, you’re right. And if you’re a singer/songwriter or a copy-editor for an advertising firm, then go right ahead. In fact, this brings us to the next usage.
This one is a bit more difficult to explain, but it’s easy to understand once I give you a few examples. You see, 당신 is okay to use if there’s no actual person physically present in front of you receiving the communication. Now think about that for a second. (But only a second.) In order for there to be “no actual person physically present in front of you”, that means that either THEY are not there or YOU are not there. See how terrible of an explanation that is? Now let’s look at some examples instead.
Songs. You hear 당신 a lot in songs because a song is not one person talking to another person. It’s a broadcast. The listener is non-specific. Even if the song is about someone in particular. Even if the song is called “Hee Jin”. Even if the lyrics of my song are “This song is for Hee Jin Lee, who lives at 302-12 Royal County, Apartment 304, Yongsan-gu, Seoul”, and there’s absolutely no doubt about who the song is for. That person is still not there in front of you, so 당신 is okay. If you wrote this song for someone named Hee-Jin and you were singing it at a concert that she was attending, it would still be okay. If, however, you write a song called “Hee Jin” for your girlfriend and then you decide to serenade her outside her window, I’d highly recommend you NOT use 당신. I’d also highly recommend that your girlfriend actually be named Hee Jin.
Advertisements. Yes, you’ll see 당신 all the time in advertisements? Why, because it’s non-personal communication for a non-specific listener. Even if YOU are there, the dude that wrote the ad is not. So it’s okay.
Direct Translation. Let’s say I show you a sentence in English and ask you to translate it for me. The sentence is, “I sent the documents to you.” Now, without any further information, how are you going to translate that sentence? If you knew that the “you” was a teacher, then you could say “선생님한테 서류를 보냈습니다.” If you knew that the “you” was your company’s boss, then you could say “사장님에께 서류를 보냈습니다.” But you don’t know who the “you” is in this case. Which is why it’s perfectly acceptable to translate it like this: “당신한테 서류를 보냈습니다.”
Other uses. Again, you’ll see and hear 당신 in other random places too. Just remember that it occurs where there’s either no specific and physically present speaker or no specific and physically present listener. A random example. I walk into a TGIFriday’s restaurant and get seated at a table. On the table is a small card with a Polaroid picture of our waitress, and above the picture is reads “당신의 웨이트리스 박민주 입니다.” Once again: non-specific audience (just happens to be me this time) and speaker is not physically present. 당신 okay!
So there’s one more way you can get away with using 당신, and that’s when you’re using it as a 3rd person reflexive pronoun. What does that mean, you ask? Hell, I don’t know. But look, here are two example sentences (taken from Naver’s online dictionary) to get you started.
어머니는 당신의 아이들을 위해 항상 기도하신다
My mother always prays for her children.
할아버지는 당신이 손수 지으신 그 집을 매우 아끼셨다
Grandfather took extra special care of the house, which he’d built with his own hands.
But 당신 is hardly ever used this way. So infrequently, I’d say, that you don’t even have to worry about remembering it. Besides, if you tried to use it like this, you’d just end up screwing it up anyway.
And then what would happen?
That’s right. Fisticuffs.