化险为夷的近义词-

2021年1月25日发(作者：李子硕)
1.
现在完成时


现在完成时用来表示之前已发生或完成的动作或 状态，
其结果的确和现在有联系。
动作或状态发生在过去
,
但它的影响现在还存在；
也可表示持续到现在的动作或

状态。
其构成：

have (has) +
过去分词
。


2.
比较过去时与现在完成时


1
）
过去时表示过去某时发生的动作或单纯叙述过去的事情，强调动作；现 在完
成时为过去发生的，强调过去的事情对现在的影响，强调的是影响。


2
）
过去时常与具体的时间状语连用，
而现在完成时通常与模糊的时间状语连用，或无时间状语。


一般过去时的时间状语
:

yesterday, last week
，
…ago, in1980, in October, just now,
具体的时间状语


共同的时间状语
:

this morning, tonight,this April, now, once
，
before, already, recently
，
lately

现在完成时的时间状语


for, since, so far, ever, never, just, yet, till / until, up to now, in past years, always,

不确定的时间状语



3
）现在完成时可表示持续到现在的动作或状态，动词一般是延续性的
，如
live,
teach, learn, work, study, know.

过去时常用的非持续性动词
有
come,
go,
leave,
start,
die,
finish,
become,
get
married
等。


举例：


I saw this film yesterday.
（强调看的动作发生过了。
）


I have seen this film.
（强调对现在的影响，电影的内容已经知道了。
）


Why did you get up so early?
（强调起床的动作已发生过了。
）


Who hasn't handed in his paper?
（强调有卷子，可能为不公平竞争。
）


She has returned from Paris.
她已从巴黎回来了。


She returned yesterday.
她是昨天回来了。


He has been in the League for three years. (
在团内的状态可延续
)

He has been a League member for three years. (
是团员的状态可持续
)

He joined the League three years ago. (
三年前入团，
joined
为短暂行为。
)

I have finished my homework now.

---Will somebody go and get Dr. White?

---He's already been sent for.

句子中如有过去时的时间副词（如

yesterday, last, week, in 1960
）时，不能使用
现在完成时，要用过去时。


（错）
Tom has written a letter to his parents last night.

（对）
Tom wrote a letter to his parents last night.

3.
比较
since
和
for

Since
用来说明动作起始时间，
for
用来说明动作延续时间长度
。


I have lived here for more than twenty years.

I have lived here since I was born..

My aunt has worked in a clinic since 1949.

Some new oilfields have been opened up since 1976.

I have known Xiao Li since she was a little girl.

My brother has been in the Youth League for two years.

I have not heard from my uncle for a long time.

注意：并非有
for
作为时间状语的句子都用现在完成时。


I worked here for more than twenty years. (
我现在已不在这里工作。
)

I have worked here for many years. (
现在我仍在这里工作。
)

小窍门：

当现在完成时< br>+
一段时间，这一结构中，我们用下面的公式转化，很
容易就能排除非延续动词在完成时 中的误使。


1) (
对
) Tom has studied Russian for three years.

= Tom began to study Russian three years ago, and is still studying it now.

2) (
错
) Harry has got married for six years.

= Harry began to get married six years ago, and is still getting married now.

显然，第二句不对，它应改为

Harry got married six years ago.
或

Harry has been
married for six years.

4. since
的四种用法


1) since +
过去一个时间点

(
如具体的年、月、日期、钟点、
1980, last month, half
past six)
。


I have been here since 1989.

2) since +
一段时间
+ ago


I have been here since five months ago.

3) since +
从句


Great changes have taken place since you left.

Considerable time has elapsed since we have been here.

4) It is +
一段时间
+ since
从句


It is two years since I became a postgraduate student

5.
延续动词与瞬间动词


1)
用于完成时的区别


延续动词表示经验、经历；

瞬间动词表示行为的结果，不能与表示段的时间状
语连用。


He has completed the work.
他已完成了那项工作。

(
表结果
)

I've known him since then.
我从那时起就认识他了。
(
表经历
)

2)
用于
till / until
从句的差异


延续动词用 于肯定句，
表示

做
……
直到
……
瞬间动词用于否定 句，
表示

到
……
，
才
……

He didn't come back until ten o'clock.
他到
10
点才回来。


He slept until ten o'clock.
他一直睡到
10
点。


典型例题


1. You don't need to describe her. I ___ her several

times.

A. had met B. have met C. met D. meet

答案
B.
首先本题 后句强调对现在的影响，
我知道她的模样，
你不用描述。
再次，
severa l times
告知为反复发生的动作，因此用现在完成时。


2.--- I'm sorry to keep you waiting.

化险为夷的近义词-

化险为夷的近义词-

化险为夷的近义词-

化险为夷的近义词-

化险为夷的近义词-

化险为夷的近义词-

化险为夷的近义词-

化险为夷的近义词-