It takes him less than an hour to finish reading a book.
spend和take都可以表示“花费”时间做某事
spend的主语必须是人,常用于以下结构:(1)spend time/money on sth.意思是在……上花费时间(金钱)。例如:I spend 2hours on this math problems.
(2) spend time/money (in) doing sth.花费时间(金钱)做某事。He spend less than an hours reading the whole book.
可以使用take
常见用法有以下几种:(1)it takes sb.+时间+to do sth.做某事花了某人多少时间。It takes him less than an hour to finish reading a book
(2)doing sth. takes sb.+时间,做某事花了某人多少时间。
finish doing sth 完成某事