“대하다 (對하다)” and “관하다 (關하다).” Both seem similar, but not the same. How different are they? The only thing I know is that “對” means “to face” and “關” means “to relate.”
Both 대하다 and 관하다 means "about" in Korean. The difference is the thing to focus.
A에 관하여 B / A에 관한 B: B is the focus
A에 대하여 B / A에 대한 B: A is the focus
Taking example sentences given by HK Lee,
- 실업 대책에 관하여 쓴 글
In most cases, the listener is interested in unemployment policy, then you emphasize there is a writing regarding it, then unemployment policy need not be emphasized as either the reader is already acknowledged the topic or the reader will realize the topic of the writing when they read it. So in this case, 대하다 is seldom used.
- 다음은 여성의 사회적 지위에 관하여 토론하도록 하겠습니다
Usually 관하다 is used as the speaker is introducing a program, which the program flow instead of the topic will be focused.
- 전통문화에 대한 관심
The speaker wants to draw audience's attention to the topic "traditional culture", so 대하다 is used.
- 강력 사건에 대한 대책
It could be that the problem of violent act is severe, so the speaker wants to focus that there is a policy regarding violent act.
대하다 and 관하다 have a meaning "about"
(In addition, 대하다 have more different meanings)
Roughly speaking, if B has a position not related to A, then A 에 대한 B.
If not, then A 관하여 B
(1) 실업 대책에 관하여 쓴 글 A writing about unemployment policy
(2) 다음은 여성의 사회적 지위에 관하여 토론하도록 하겠습니다 We will discuss about woman's position in society
(3) 전통문화에 대한 관심 Interest about traditional culture
(4) 강력 사건에 대한 대책 Policy about violent act