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英语动词不定式 有哪些

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英语动词不定式 有哪些
英语动词不定式 有哪些
关于现在完成时,现行教材着重处理了“已完成用法”和“未完成用法”.无论哪种用法都强调一点,即过去动作给现在带来的结果或对现在造成的影响.因此现在完成时不是属于过去时,而是属于现在时的范畴.但在高考复习中,还应该注意一些相关的问题才能对此时态有一个全面的把握.
一、
“已完成用法”是针对瞬间动词(即非延续性动词)而言的,动词通常可以表示在说话之前已经完成,而后果或影响至今仍存在.这些瞬间动词常用的有:start,finish,turn
off / on,lose,become,leave,open,close,join等.例如:
Li Ming has just turned off the light. 李明刚把灯关上.
I’ve finished my homework now. 现在我已经做完作业了.
I have lost my pen. 我把笔弄丢了.
She has become a teacher. 她已经当了一名老师.
表示“已完成用法”的对应时间状语只能是表示时间点的词,如just, now, already, yet, not ...
yet,或者干脆不带时间状语,如上述例句中的后两个.
但是瞬间动词与时间段状语如for a week / three
days连用时,并非指瞬间动词的动作延续了多久,而是包含下述两层意思:①谓语动作已完成,②接续动作要持续多久.例如:
He has come here for three days. 他来了,准备待三天.
He has left Shanghai for New York for two years.
他已离开上海去纽约,要在那里住两年.
显然若把上述两句理解成“他已来了三天”和“他已离开上海去纽约两年了”都是错误的.
二、
“未完成用法”是针对延续性动词而言的,主要表示从过去开始的动作已持续到现在,而且还会继续下去.动词多为work,study,live,know等,所带的时间状语也是持续性的,如lately,these
days,since 2 days ago,since 1991,for a long time,so far,up to
now等.例如:
I have studied English since 1995. 我从1995年起开始就学习英语.
He has lived here for two years. 他住在这儿已经两年了.

但是延续性动词的完成时不带时间状语则不是说明“过去开始的动作已持续到现在,而且还会继续下去”,而是说明“动作已经结束,而影响还留在现在”.例如:
She has been a teacher. 她当过教师.(含义:她现在不是教师了,在干别的工作.)
(比较:She has been a teacher for three years.
她当教师已有三年.——现在还是教师.)
三、
按英语语法规律,瞬间动词不能和表示时间段的状语连用,但是汉语里,却可以这样,因此英汉两种语言在转换时必然有障碍.在这里,只要抓住转换规律,矛盾就会迎刃而解.现把中学阶段由瞬间性转为延续性的若干对动词列举于下面:
die → be dead
go out → be out
open → be open
begin / start → be on
buy / get → have / keep
get up → be up
arrive in / come to / get to / reach → be in
close → be closed
fall / become → be
marry → be married to
get to know → know
finish / end → be over
leave / move → be away / be out of
join → be in
borrow → keep
catch → have
come back → be back
put on → wear / have on
wake → be awake
此外还须记住一些由瞬间动词转换为延续性动词的常用句型:
1) 瞬间动词的过去时 + ... ago → 延续性动词的现在完成时 + for + 一段时间.例如:
他参军三年了.
He joined the army three years ago. → He has been a soldier
for three years.
电影已开始十分钟了.
The film started ten minutes ago. → The film has been on for
ten minutes.
2)使用句型“It is / has been + 一段时间 + since +瞬间动词的一般过去时”.例如:
他父亲已去世两年了.
It is / has been two years since his father died.
从上述几点可以看出,在英语学习中,建立起延续性动词和非延续性动词的概念对我们是非常重要的.
四、 正确理解since引导的时间状语从句.
since引导时间状语从句有三种情况:
1) “since + 瞬间动词的过去时”.其从句中的动作已在过去完成,这是我们熟知的句型.例如:
We’ve been friends since we met at school. 我们自从在学校认识以来一直是朋友.
2) “since +
延续性动词的过去时”.它的要点是:时间从延续动词结束后计算,这与瞬间动词的计算不同,现行教材基本没有讲到.例如:
It is three years since he smoked. 他戒烟已经三年了.(= It is three
years since he stopped smoking.)
3) “since + 延续性动词的现在完成时”.其从句的动作或状态延续至今.例如:
They have the deepest affection for the old professor since
they have worked with him.
自打同这位老教授一同工作以来,他们就对他怀有最深切的感情.(他们和教授现在仍然一起共事)
五、 注意以下几个完成时的句型在含义上的区别.
1) have gone to somewhere表示“去了某地(说话时当事人不在场)”,用于第三人称.例如:
He (They) has (have) gone to Beijing. 他(们)去了北京.(现在仍在北京)
不能说:I / We / You have gone to Beijing.
2) have been to
somewhere“去过某地(现在已经回来了)”,可用于各种人称.所要求的时间状语是与倍数相关的词,如once,ever,never,twice,several
times,many times等.例如:
I have never been to the Great Wall. 我从未去过长城.
How many times have you been there this year? 今年你去过那里多少次?
3) 在“It / This is the first / second time ...
that从句”中,that从句部分要用现在完成时.例如:
It is the first time that I have visited the city.
这是我第一次到这座城市.
This is the second time that they have finished the work ahead
of time. 这是他们第二次提前完成工作.
4) “This is the + 形容词最高级 + 名词 + that从句”结构中,that从句要用现在完成时态.例如:
This is the best film that I’ve (ever) seen. 这是我看过的最好的电影.
六、 瞬间动词的完成时的肯定式一般不与一段时间状语连用,但是它的否定式和被动式常与一段时间状语连用.例如:
We haven’t heard from Jane for a long time. 我们很久都没有收到简的来信了.
七、介词短语如in the past years,in the last few years,over the last
century,during the past ten years以及since two years
ago等,虽然含有明确的过去时间,但句子仍然要用现在完成时.(现在完成时就是动词不定式)