英语语法大全|现在完成时的结构和用法
(一)基本结构
现在完成时的句子结构一般为:
主语+have/has+过去分词+其他成分
如:
We have already had lunch.
He has been away for a week.
(二)主要用法
1、表示过去发生并且已经完成的动作对现在造成的影响或结果。此时,常和谓语动词一起使用的副词有already、just、never、ever、yet等。如:
They have already come back from the museum.
She has already finished her homework.
2、表示过去发生的动作持续到现在,并且有可能会继续持续下去。此时,常和谓语动词一起使用的标志性词语主要有for和since,而且此时的谓语动词往往是持续性动词(如stay、keep、wait等)。如:
I have lived here for ten years.
He has kept the clavichord since thirty years ago.
3、表示从过去某一时间到说话时这段时间中反复发生的动作。此时,常和谓语动词一起使用的主要是表频度的副词often、always、seldom、never等,以及表次数的单词或短语(如once、twice、three times)。如:
You have never listened to me like this before.
She has ever been to France.
They have visited the Summer Palace many times.
(三)动词的过去分词
1、规则变化
其变化规则与动词的一般过去时基本相同,主要是在词尾加-ed或-d。具体的有:
1)直接加-ed。如:worked、played。
2)以不发音的e结尾的动词后加-d。如:lived、danced。
3)以辅音字母加y结尾的动词后改y为i,再加-ed。如:studied、cried。
4)以重读闭音节结尾的动词后,双写最后一个辅音字母再加-ed。如:stopped、patted。
2、不规则变化
如果结合动词的过去式,动词的过去分词的不规则变化中,又有一些相对的规则现象。如:
1)AAA型。如:put put put;read read read。其中,read的过去式和过去分词虽然拼写时一样的,但其发音与原形不同,ea不再读作[iː],而是[e]。
2)AAB型。如:beat beat beaten
3)ABB型。如:keep kept kept;sit sat sat
4)ABC型。如:lie lay lain;drink drank drunk
5)ABA型。如:run ran run;come came come
(四)标志性词语
1、副词already、just、never、ever、yet等。如:
She hasn't arrived in Scotland yet.
They have just left for Shanghai.
2、for和since。for+一段时间,since+具体时间。如:
He has learned Italian for five months.
He has learned Italian since five months ago.
3、so far和up to/till now。表示“迄今为止”。如:
So far, no one has heard any news about her.
She has read fifty books up to now.
4、recently、lately等表示“最近;最新”的副词和形容词。如:
I've met her on several occasions recently.
He hasn't had enough sleep lately.
5、in the past/last+一段时间,表示“在过去的...时间里”。如:
In the past few years, new buildings have sprung up all over Beijing.
He had aged rapidly in the last few months.
6、次数。如:
I've tried many times, but there's no way.
He has been there at least twice.
(五)have been to/have gone to/have been in
1、have been to
表示“去过已回”。句子主语就在现场。如:
They have been to Rome many times.
She has been to Shanghai more than once.
2、have gone to
表示“去了未回”。句子主语不在现场。如:
Jerry has gone to Hangzhou.
Mary has gone to Finland.
3、have been in
表示“一直待在某地”。如:
We have been in Beijing for five weeks.
They have been in China since 2012.
(六)短暂性动词和延续性动词
所谓短暂性动词主要是指一旦发生马上就结束的动作,也叫瞬间动词,如die、marry、leave等。而延续性动词主要是指可以一直持续进行的动作,也叫持续性动词,如learn、live、talk等。
两类动词都可以用于现在完成时,但是短暂性动词不能与表示一段时间的时间状语连用。此时,需要把短暂性动词改为相应的表状态的动词或短语。如:
错误:He has died for ten years.
正确:He has been dead for ten years.
错误:She has married him since five years ago.
正确:She has been married to him since five years ago.
(七)句型转换
因为“have/has done”中的have/has是助动词,所以在进行句型转换中要注意不需要再另外借助助动词do/did/does,而是直接借用have/has。如:
肯定句:He has lived here for the last few years.
否定句:He hasn't lived here for the last few years.
一般疑问句:Has he lived here for the last few years?
特殊疑问句:How long has he lived here? (划线部分为for the last few years)