spend 通常表示“某人花费时间或金钱做某事”，主语必须是人。
基本结构：
sb. spend(s) time/money on sth.sb. spend(s) time/money (in) doing sth.例句：
She spends two hours on homework every day.
They spent a lot of money buying a new car.
take 常用于表示“做某事花费多少时间”，常用句型为“It takes...”。
基本结构：
It takes sb. time to do sth.例句：
It takes me 30 minutes to walk to school.
It took them three days to finish the project.
It spends me two hours to do homework.（错误！不能用 spend 构成 it 句型）It takes me two hours to do homework.I take two hours on my homework.（不自然）I spend two hours on my homework.