2012-1-9 10:39:46 版主
1. come & be here [误] He has come here for three hours. [正] He came here three hours ago. [正] He has been here for three hours. come是瞬间动词，不是延续性动词，在肯定句中不能与表示一段时间的状语连用。而要与表示一段时间的状语连用，就要用延续动词。 与此同类的还有borrow/lend-keep; join-be in/at; die-be dead; buy-have; leave-be away,etc.
2. cost & take & spend & pay [误] I cost a lot of time to read stories. [正] It cost me a lot of time to read stories. [正] I spent a lot of time reading stories. cost除了钱的花费以外，还能表示时间上的花费，但常用物做主语。spend句子主语是人，可指花费时间和金钱，但后面的动词要用-ing形式，后面也可跟名词短语，介词用on。pay句子主语是人，常与for连用，buy也常与for连用，但花费“钱”要放在介词for后面，而pay则放在介词for前面。
3. join & take part in [误] He joined the League for two years. [正] He joined the League two years ago. [正] He has been in the League for two years.[正] He has been a League member for two years. join指“参加”组织，成为一个成员，join sb.意思是“加入某人”，take part in指参加活动特别是大的运动；如指“参加…多长时间”就要用延续动词be in或be a …member，而不能用join。