基于
jīyū · HSK 7
on the basis of
🧱 基 = base/foundation + 于 = at/upon; so 基于 = built upon a base, on the basis of
基 is the foundation (same 基 as 基础, foundation/groundwork), and 于 marks at or upon. Together: standing upon a foundation, hence on the basis of or because of.
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.