You finished this day
Reacting to a stage
Fan reactions come in two kinds: slang that sounds big, like 대박 (daebak) and 미쳤다 (michyeotda), and ordinary compliments anyone can use, like 멋있다 (meositda) 'cool'. Today covers both, and who can hear which. By the end you can react to a performance in Korean, and pick the version that suits the person next to you.
The big four
Each of these is a reaction to a stage that went well. All four are casual:
Two of the four are past tense, and that is the trick: 미쳤다 is 'has gone mad', so 'is mad now', and 찢었다 reports something finished. The -다 ending is the plain dictionary form, and used as an exclamation it is aimed at nobody, which is why fans can shout it at a screen. 대박 and 레전드 are nouns and need no ending. All four are slang, but of different ages: 대박 is old enough that parents say it, while 찢었다 is newer and mostly heard from people under thirty.
Ordinary compliments
These three are standard Korean, not slang. What changes is who hears you:
Said [머시써요], like 맛있어요. For a finished stage, use the past: 멋있었어요 (meosisseosseoyo).
Past in form, present in meaning: 잘생기다 is 'to be well made', and the past says he has turned out that way.
The ㅂ of 귀엽다 turns into 우 before -어요, so it is 귀여워요, never 귀엽어요.
The first column is the dictionary form ending in -다, used as a blurt. Because it is said to nobody, it sits outside the speech levels, and a polite speaker can murmur 와, 멋있다 in front of a teacher without being rude. The moment you say it to someone, you have to choose a level: 멋있어 to a friend, 멋있어요 to everyone else. The formal 멋있습니다 (meositseumnida) exists, but you will mostly hear it from a presenter on a stage, not from the fans in front of it.
Fan reaction, real-life reaction
The left column is for friends and comments. The right is for a stranger, an older person or someone at work:
The slang is not insulting, but it comes from a register built on exaggeration: madness, tearing things, legends. Among fans the exaggeration is the point, and a plain 좋았어요 can sound flat. With someone older, or at work, the same exaggeration sounds as if you are not taking them seriously. There is also the literal meaning: 미쳤다 about a person means 'they've gone mad', and a listener who is not a fan may hear that first.
Carry over, from earlier days
Check yourself
8 questions. Get 5 right to finish the day.