现在完成时态.doc

现在完成时
：现在完成时由助动词have + 过去分词构成，助动词have 有人称和数的变化。第三人称单数用 has，其余用have.
现在完成时的否定式直接在助动词后面加上not、疑问式是把助动词提到主语之前。以study 为例，其否定式、疑问式和简单回答形式如下：
否定式
疑问式
I have not (haven’t) studied….
Have I studied…?
You have not (haven’t) studied….
Have you studied…?
He has not (hasn’t) studied….
Has he studied…?
否定疑问式
简单回答（肯定/否定）
Have I not (Haven’t I) studied…?
Yes, you have. No, you haven’t.
Have you not (Haven’t you) studied…?
Yes, I have. No, I haven’t.
Has he not (Hasn’t he) studied…?
Yes, he has. No, he hasn’t.
二．用法：
。说话人强调的是该动作或状态对 现在的结果或影响。
My daughter has just gone out. 我女儿刚出去。
I’m sure we’ve met before. 我肯定我们以前见过面。
She has arrived. 她到了。
，往往和包括现在在内的表示一段时间的状语连用，如recently, already, just, lately, for…, since…,yet等。如：
I haven’t heard from her these days. 这些日子我没有收到她的信。
We haven’t seen you recently. 最近我们没有见到你。
They have been away for two years. 他们离开已经两年了。
She has been with us since Monday.
★注意：
since和for的区别
since后接时间点，如1993，last term, yesterday, the time I got there
for后接一段时间，表示“长达多久”，如ten years, a while, two days等。
Exercise: 用since和for填空
1. Jim has been in Ireland ______ Monday.
2. Jill has been in Ireland ______ three days.
3. His aunt has lived in Australia ______15 days.
4. Mary is in her office. She has been there ______ 7 o'clock.
5. India has been an independent country _