～者
～しゃ · ～sha · JLPT N2 · noun
person
🧑 ～者 works like English -er: 学者 gakusha = study + er = scholar
者 is a suffix that turns an activity into the person who does it. 医者 isha = medicine + er = doctor; 記者 kisha = record + er = reporter. The top part 耂 is the old-person radical, a reminder that it marks a person.
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.'