消防安全文章-

2021年1月25日发(作者：博士隆)




























现在完成时




一．

构成







助动词

have/has +
过去分词


例
:
肯定句

I have worked.























He has worked.
否定句

I have not (haven't ) worked.













He has not (hasn't )worked .
疑问句

Have you worked ?





















Has he worked ?
回答
Yes
，
I have. /

No , I haven't .













Yes, he has./ No, he hasn't.

二．

功能及意义


1.

表示一个动作发生在过去，
对现在仍有影响，
但没有具体的过 去时间修饰。
常
由下列副词修饰：

ever
曾经，

never
从不，

already
已经，

ye t
还（未）
，
（
yet
只用在否定句和疑问句中）
，


just
刚刚，

recently
，
lately
近来，

so far
迄今为
止
= until now, up to now
，

before
以前


例：
Have you ever been to the Great Wall?
你曾经去过长城吗？

I have never heard of such a man.
我从没有听说过那个人。

We have just had lunch
我们刚刚吃过午饭

I have already returned your money.
我已经把钱还给你了。

I haven't found my book yet.
（否）我还没有找到笔记本


Have you done your homework yet?
（疑）

你做作业了吗？

Have you heard from him recently ?
你最近收到他的来信了吗？





So far, no one has made any mistakes yet.
迄今为止

还没有人犯错误





I have never traveled by plane before .
我以前从来没有乘飞机旅行过



2
表示一个动作发 生在过去，一直持续到现在刚刚结束或者仍在继续。常常与
下列时间状语连用：


→
for +
一段时间

I have learned English
for 8 years---
我已经学习英语八年了


→
since +
过去的一个时间点

I have learned English since 2001---
我从
2001
年开始学英语


→
since +
一段时间
+ ago
I have learned English since 8 years ago---
我从八年前开始学英语

→
since +
时态为一般过去时的时间状语从句

I have learned English since I was 5 years old---
我从五岁开始学英语

→
in the past/last +
时间段

We have had two English exams in the past two months
在过去的两个月里我们进行
了
2
次英语考试

Great changes have taken place in my hometown in the past ten years
近十年来我的

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