COST花费的意思,一般是说某个东西花了你多少钱,比如The coat costs 20 pounds. TAKE是指做什么事情花费多久,比如说It takes(took) sb sometime to do sth. SPEND是你的主动权,你花了多久,多少钱去干什么,去买什么。比如说I spent 2 days on doing my homework/I spent 20 pounds to buy this coat.PAY是你付款,比如I paid 20 pounds for this coat.