关于
guānyū · HSK 4
about
关于 = 关 (close/concern) + 于 (regarding); 'concerning regarding'
关 carries the sense of involvement or concern, and 于 is a classical particle meaning 'at/regarding'. Together 关于 marks the topic a statement is concerned with — English 'about' or 'concerning'.
关 — door 门 + simplified 关 inside
关 is the simplified form of 關. The traditional character showed a gate (門) with a bolt or crossbar inside, depicting a barred door — hence 'to close' or 'shut'. Meaning later extended to 'pass' (a guarded gate), 'barrier', and figuratively 'concern' or 'connection'.
于 — two horizontal strokes 二 + vertical hook 亅
于 originated as a pictograph of breath or sound flowing outward, depicting exhalation through a passage. In oracle bone script it resembled a curved line showing motion or extension. Over time it became a grammatical preposition meaning 'at,' 'in,' or 'to,' losing its original concrete sense.