Here we have two grammatical principles which differ from each other just slightly, and which cannot be neatly translated into English. Let’s look at them one by one.
-구나 / -군요
This particle is used to express the nuance that the speaker has just found out about or realized something. It sort of equates to “Oh, I didn’t realize X is the case.” or “Oh, now I see that X is the case.” It also carries a fairly strong nuance of talking to oneself or musing aloud about something.
For example, let’s say your roommate goes grocery shopping. Later that day you open the fridge and your eyes fall on a fresh carton of eggs. You might say to yourself, “계란 샀구나.” which would roughly translate to, “Oh, I see they bought eggs.”
This principle works for present, past, and future tense. The meaning changes ever so slightly for future tense. It adds a nuance of probability. Sort of like saying, “Oh, I just realized X will probably be the case.”
Let’s say you have just 20 bucks to your name, and you head to the movies thinking tickets are like 8 bucks and popcorn is 10. You meet your friend on the way, and they mention to you that they heard the theater just upped its prices on everything by 20%. You might say, “그럼 돈이 부족하겠구나!” meaning roughly, “Oh, then I probably won’t have enough money.”
구나 is used in 반말, or informal speech. 군요 is used in 존댓말 or formal speech. Let’s look at how to attach it in the present tense.
*Reminder: every verb and adjective in Korean ends with 다. Remove 다 and you are left with the “root” of the word.
Adjectives: attach it directly to the root.
Eg: 행복하다 (to be happy) – 행복하구나
Nouns: if the noun ends with a consonant, add 이 before 구나. Otherwise just add 구나.
Eg: 강아지 (puppy) = 가아지구나
뱀 (snake) = 뱀이구나
Verbs: add 는 before 구나
Eg: 오다 (to come) = 오는구나
This particle can also be used in past and future tense. Just add it directly to the conjugated root.
*Note: these examples are not as I’ve translated them in the actual song translations. They are translated differently here to emphasize the meaning of this particle.
뱁새 (Silver Spoon):
아 노랗구나 싹수 ~ “Ah, so the sprout is yellow.”
Original adjective: 노랗다 – to be yellow
켜궜구나 너의 switch ~ “I see you’ve turned your switch on.”
The meaning of 네 is quite similar to the meaning of 구나. They are both used to talk about something the speaker just realized. The main differences are that 네 has less of a feeling of talking to oneself than 구나 and that 네 carries a stronger nuance of being surprised or amazed by something – in a positive or a negative way.
Let’s say you go out for Karaoke night and your friend who you’ve never heard sing before turns out to be an amazing singer. When they head back over to your table after their song, you might say (and I don’t know why I hear this in j-hope’s voice) “야, 너 노래 잘 하네!” This would roughly translate to “Hey, you’re a good singer!” It carries the nuance that a: you didn’t realize that until just now, and b: you’re surprised/impressed/amazed by it. That’s a lot of meaning packed into a single syllable.
This one’s a little simpler grammar wise. Let’s look at the present tense. Note that for this one, you can make it formal by simple adding 요 at the end.
Adjectives/verbs: add it to the root
Eg: 행복하다 > 행복하네!
오다 > 오네!
Nouns: insert 이 in between if the noun ends in a consonant. Otherwise add it to the noun.
Eg: 강아지 > 강아지네!
뱀 > 뱀이네!
네 also works in past and future tense in the same way that 구나 does. Just add it to the conjugated root.
*Note: like with 구나 these examples are not as I’ve translated them in the actual song translations. They are translated differently here to emphasize the meaning of this particle.
내 방을 여행하는 법 (Fly To My Room):
오래된 책상도 달라진 햇빛도 특별해 보이네. ~ “Even my old desk and the changing sunlight look special.” [and I’m surprised/amazed by this]
Original verb: 보이다 – to be visible, to show, to look a certain way
Life Goes On:
혼자 가네 시간이 ~ “[I’m amazed/surprised at how ] time goes by on its own.”
Original verb: 가다 – to go
이상하지 않은가 (Strange) by Agust D:
눈감은 세상에서 눈 뜬 자 이젠 눈을 멀게 하네. ~ “[I’m amazed/surprised to discover that…] In a world with its eyes closed, the one who opened their eyes is now made blind.”
Original verb: 하다 – to do
오늘의 선수 입장하시네 ~ “Oh, wow, in comes the player of the day!”
Original verb: 입장하다 – to enter
난 자유롭네 ~ “I’m free [and I’m amazed or surprised by that].”
Original adjective: 자유롭다 – to be free