Open a Korean group chat and a lot of it will not look like Korean. Strings of bare consonants, three-syllable compounds you cannot find in a dictionary, and rows of ㅋ.
Most of it follows two or three simple principles.
초성체: consonants only
Korean lets you drop the vowels and keep the initial consonants. The result is unreadable to a learner and instantly clear to a native speaker.
| Slang | Full form | Meaning |
|---|---|---|
| ㅇㅇ | 응응 | yeah |
| ㄴㄴ | 노노 | no |
| ㅇㅋ | 오케이 | okay |
| ㄱㅅ | 감사 | thanks |
| ㅅㄱ | 수고 | good work |
| ㅁㄹ | 몰라 | dunno |
| ㄱㄱ | 고고 | let's go |
| ㅊㅋ | 축하 | congrats |
This is by far the most common type, and once you know the pattern you can often decode new ones by guessing at the vowels.
Laughing and crying
ㅋㅋㅋ is laughter. It comes from 크크크.
The length is meaningful, and this is worth getting right.
| Form | What it signals |
|---|---|
| ㅋ | dry, sometimes cold |
| ㅋㅋ | polite acknowledgement |
| ㅋㅋㅋㅋ | actually amused |
| ㅋㅋㅋㅋㅋㅋㅋㅋ | genuinely laughing |
A single ㅋ in response to a joke can read as dismissive. Two is neutral. If in doubt, use three or four.
ㅎㅎ is softer — closer to a smile than a laugh, and slightly more polite. Many people use ㅎㅎ with colleagues and ㅋㅋ with friends.
ㅠㅠ and ㅜㅜ are crying eyes. Used for disappointment, exhaustion, or mild complaint, often not seriously.
배고파 ㅠㅠ — I'm hungry :(
Shortened phrases
Korean compresses long phrases into two to four syllables constantly, and many of these have become normal words.
| Slang | From | Meaning |
|---|---|---|
| 아아 | 아이스 아메리카노 | iced americano |
| 열공 | 열심히 공부 | studying hard |
| 갑분싸 | 갑자기 분위기 싸해짐 | the mood suddenly died |
| 인싸 | insider | a socially central person |
| 아싸 | outsider | a loner |
| 최애 | 최고 애정 | favourite (bias) |
| 노잼 | no + 재미 | not funny |
| 꿀잼 | 꿀 + 재미 | very fun |
아아 is used in actual cafes by actual adults, not just online. It has crossed over completely.
Reaction words
| Korean | Meaning |
|---|---|
| 헐 | what / no way |
| 대박 | amazing, huge |
| 진짜? | really? |
| 실화냐 | is this real? |
| ㅇㅈ | agreed |
| 어쩔 | whatever |
헐 and 대박 are so common they barely count as slang anymore. You will hear both spoken constantly.
Fandom vocabulary
A whole layer of slang comes from fan communities and has spread into general use.
| Korean | Meaning |
|---|---|
| 덕후 | an obsessive fan (from Japanese otaku) |
| 입덕 | falling into a fandom |
| 탈덕 | leaving a fandom |
| 최애 | favourite member |
| 존맛 / JMT | extremely delicious |
입덕 and 탈덕 are genuinely useful words with no English equivalent — the moment you become a fan and the moment you stop.
Where not to use it
This matters more than the vocabulary.
Never in work messages to someone senior. ㅋㅋ to your boss reads as unserious.
Never in email. Korean business email is formal.
Careful with people much older. Many will not decode 초성체 quickly, and using it can come across as excluding them.
With friends your own age, it is expected, and typing full formal sentences in a casual chat reads as stiff.
A caveat about slang
Internet slang dates fast. Some entries here have been stable for a decade — ㅋㅋ, 헐, 대박 — while others cycle out within a year or two.
The consonant abbreviations and the laughter conventions are the durable part and worth learning. Trend words are worth recognising and not worth chasing.
If you want the foundation that all of this is built on, K-PATTO episodes are ordinary spoken Korean — the full forms that the abbreviations come from. The first ten are free at K-PATTO.