By repetition sign, I mean something that is like
々 in Japanese and Chinese.
In both Japanese and Chinese,
々 can be used to suggest a repetition of the previous character. For example,
人人 can be written as
人々. In Japanese, there is also a repetition sign for kanas (
Therefore, I am wondering whether there is such a sign in Hangul so that
똑똑하다 can be written as something like