者
もの · mono · JLPT N3 · noun
person
🧑 mono sounds like mono = one: 者 is the one who does the thing
As a suffix it reads しゃ: 医者 = medicine + person (doctor), 学者 = study + person (scholar). Don't mix it up with 物, also read もの, which means thing. 者 is for people, 物 is for objects.
者 — old/elder 耂 + say 曰
Originally depicted sugarcane or a similar plant, but the form was reanalyzed as 耂 (old) over 曰 (say). It became a grammatical suffix meaning 'one who…' or 'the…thing,' nominalizing verbs and adjectives. Today 者 mainly marks agents or categories, as in 学者 'scholar' or 记者 'reporter.'