아래 문장에서 동사를 중심으로 문법 설명 부탁드려요~
Leave 뒤의 knowing과 hating은 분사구문인지
왜 앞에는 he ever learnt고 뒤에는 had learnt고 갑자기 끝에는 ever knew인지.. 이해가 잘 안가요..

A boy who leaves school kowing much,but hating his lessons, will soon have forgotten almost all he ever learnt; while another who has acquired a thirst for knowledge,even if he had learnt little, will soon teach himself more than the first ever knew.