因为它的主体是不一样的，所以区分它的使用方法相当重要
例如
It take sb. sometime to do sth.
spend on /spend doing
详细点的：
spend作动词用，意思是“花费（钱、时间）；度过”。常与介词on连用，短语spend…on…表示“在某事/物上花费钱或时间”。如：
she will spend her holiday in Japan.
He spent a lot of money on books.
spend…on后面通常跟名词，若为动词，要用spend, in doing sth花费财力或时间做某事。
如：I spent half an hour in copying the text.
My mother spends an hour on the housework every clay.
take当“花费”讲时，常用在句型It takes sb. some time to do sth中，它表示“花费某人一段时间做某事”。句型中的it是形式主语，不定式知语to do sth是真正的主语，take的形式随时间状语而变。如：
It takes me two hours to do my homework every day.
It took them ten years to finish the invention.
It will take her three hours to get there by bike next time.
要表达“花钱买东西”可以用lost, pay和spend；要表达“花时间做某”可以用spend和take。
如：The jacket cost him 98 yuan.
He paid 98 yuan for the jacket.
He spent 98 yuan on the jacket.
She spends half an hour on English in the morning.
It takes her half an hour to learn English in the morning.
均可表示“花费”，但在用法和搭配等有很大区别。现分述如下：
一、从所涉及的主语来看
spend 的主语只能是人，不能是事或物；take 的主语可以是事或物(包括形式主语 it)也可以是人。如：
I have spent all day looking for you. 我花了 1 整天找你。
It took me an hour to write the letter. 我写这封信花了 1 个小时。
The letter took me an hour (to write). (译文同上)
I took an hour to write the letter. (译文同上) (from
www.yywords.com)
2. 从所涉及的宾语来看
take 的宾语通常是时间，而 spend 的宾语则可以是时间或钱。如：
It took her two hours to walk to the station. 走路去车站花了她两小时。
He spends much time (money) on books. 他花了很多时间读(钱买)书。
按传统语法，take 的宾语通常是时间，但在现代英语中，用钱作其宾语的现象已很普遍。如：
It takes a lot of money to buy a house. 买一座房子要花一大笔钱。
3. 从所采用的句型结构来看
(1) 通常句型为：
sb spends time (money) on sth 某人在某一方面花多少钱
sb spends time (money) in [on] doing sth 某人在做某事方面花多少钱
it takes sb time (money) to do sth = it takes time (money) for sb to do sth 做某事花某人多少时间或钱
sth takes sb time (money) to do 某事花某人多少时间或钱去做
sb takes time (moeny) to do 某人花多少时间或钱去做某事
(2) 用于以上意义时，take 通常不用于被动语态，而 spend 则可以用于被动语态。如(from
www.yywords.com)：
误：Two hours was taken to do the work.
正：Two hours was spent on the work. 做这工作花了两个小时。
4. 从各自的比喻用法来看
(1) spend 表示“消耗”、“用完”。如：
I’ll spend no more breath on him. 我不会再和他费唇舌。
He spent great efforts to help me. 他费了很大的劲儿来帮我。
(2) take 表示需要人力(精力、劳力等)。如：
It takes patience. 做这工作需要耐心。
It takes two to make a quarrel. 一个巴掌拍不响。
It took three men to lift the box. 抬这个箱子要 3 个人。
追问我问的是它和“spent”，不是“take”啊！！！
追答spend 指某人花费多少时间（钱）做（在）…sb.+spend+钱/时间+on sth./(in) doing sth.eg:He spent 10 yuan on the pen.这支笔花了他十元。 He spent 10 yuan (in) buying this pen. 他花了十元买了这支笔。
呵呵，不好意思。其实主要还是看句子中的时态问题。你搞清时态问题，就好办了