初中英语现在完成时详解.doc

现在完成时 一、现在完成时构成 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. 二、现在完成时用法 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. 她到了。 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, 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. for+时段since+过去一个时间点（译为：自从……以来）since+时段+agosince+从句（过去时）It is+时段+since+从句（过去时）Mary has been ill?for three days. I have lived here?since 1998. 注意： since和for的区别 since后接时间点，如1993，last term, yesterday, the time I got therefor后接一段时间，表示“长达多久”，如ten years, a while, two days等。 表示短暂意义的动词如arrive, leave, borrow, buy, begin, start, die等，在完成时当中不能和表示一段时间的状语连用，因为它们表示的动作不可能持续。因此，不能说： He has come here for 2 weeks. × The old man has died for 4 months. × They have left only for 5 minutes. × has gone (to),has been (to), has been (in)?的区别Have/Has gone(to) :去了(现在不在说话现场可能在路上和已经到)Where is your father?He has gone to Shanghai. Have/Has been (to) :去过（已不在去过的地方）My father has been to Shanghai. Have/has been in：呆了多久（还在所呆的地方）My father has been in Shanghai?for two months. /since two months ago. 5、现在完成时不能和表示过去的时间状语连用，如yesterday, last year, in 1976, two days ago, just now, when I came in，但可以和already, yet, sometimes, always, often, before, lately, recently, once, twice, ever, never等连用。不能与when连用现在完成时往往同表示不确定的过去时间状语连用例如： She has already come. 她已经来了。 I haven’t read it yet. 我还没读过这个。 I h