以前
yǐqián · HSK 2
in the past
⏪ 以 = by/using + 前 = front/before → 'by before' = formerly, in the past
前 means front or before in time; 以 is a function word meaning by/with. Together 以前 marks a point before now. Compare 以后 (yǐhòu, afterwards), where 后 means back/after — same pattern, opposite direction.
以 — phonetic 㠯 (plow/tool) + 人 (person)
Originally a pictograph of a hand-held plow or tool (㠯), later combined with 人 (person) to suggest 'using' something. The core meaning 'to use' extended metaphorically to 'by means of', 'with', and 'because of'. In modern Chinese it functions mainly as a grammatical particle.
前 — top 丷 + 一 + 月 (moon) + 刂 (knife)
Originally written 歬, depicting a foot 止 above a boat 舟, meaning to advance or go forward. Over time the form evolved and the knife radical 刂 was added, while 止 and 舟 fused into the modern shape. The core meaning 'front, before, ahead' has stayed consistent.