一、时态讲解:现在完成时(1)构成: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
(2)用法:1)现在完成时通常表示在说话之前已经完成的动作或存在的状态
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
2)表示持续到现在的动作或状态,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