英语完成时态中经常会用一个时间概念的单词结尾,而与之相连的词是since或for,比如:
1、I have been here since 2012.
2、I have been here for five years.
这两个句子说的意思是一样的,但是表述的方式不同。我们再看两个例句:
3、The piano has been repaired since it was broken.
4、The piano has been taken away for two weeks.
这里总结一下:
在完成时态中,since连接的是表示时间点的词,比如2012,last Saturday等,而for连接的则是表示一段时间的词或词组,比如 six months, a long time 等。而且,since除了连接表示时间点的词之外,还可以连接一个动作的实施结果,比如上面例句3中的“since it was broken”等。
我们多用几个例句说明一下:
5、It has been two years since he came to see me.
6、She hasn‘t studied in school since his father made big money.
关于since要特别注意,since连接的动作中动词如果是一般过去时的时候,主句中的动词用现在完成式,但是在口语中,有时候也会用since引导现在完成时,如:
7、It has been four weeks since I went to Paris.
8、It has been four weeks since I have gone to Paris.
以上两个例句的情况,只适用于since连接的动词是短暂动词。如果是表示持续动作的动词,则since引导的句子用一般现在时和现在完成时,句子的含义是不同的。比如:
9、My mother has taken care of me since I was ill.这里的含义应为“自从我病愈以来”。
这一点需要大家多体会一下。
多练习,多阅读,可以有更深的体会。
顺便再讲一下什么是短暂动词,大家请看下面的例词:
buy
die
open
close
borrow
leave
come
start
join
等等,大家也可以记一下。