有所
yoǔ suǒ · HSK 7
somewhat
有所 = 有 (have) + 所 (that which) -> have-something -> somewhat, to some extent
有 means there-is and 所 marks that-which; together have-that-which softens into a vague some amount. Use 有所 before a verb to say a bit of it happened, as in 有所改善 = somewhat improved.
有 — hand 𠂇 + moon/meat 月
Originally depicted a hand holding a piece of meat (月 here is the 'meat' radical, not moon), expressing the idea of possessing something. Over time the meaning broadened from 'to hold/possess' to the general sense of 'to have' or 'there is/exists'.
所 — door 戶 (left) + axe 斤 (right)
Originally a sound: an axe (斤) chopping wood near a door (戶), with 戶 also hinting at the pronunciation. Over time it was borrowed to mean 'place' or 'location,' and later became a grammatical particle nominalizing verbs ('that which…'). The concrete 'chopping' sense faded entirely.