Kakao is a dialect

ㅋㅋ light laugh. ㅋㅋㅋㅋ you actually found it funny. ㅎㅎ milder, older, sometimes distant.

ㅠㅠ / ㅜㅜ is the tear. ㅇㅇ means yes, I read it. ㄱㄱ let's go. ㅇㅋ okay.

Replying 네 to a friend in Kakao can feel like a corporate ticket. Match their 반말 once they started it.