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现在完成时和进行时

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怎么区别现在完成时和现在进行时?
解题思路: 如下
解题过程:
现在进行时:
1.概念:表示现阶段或说话时正在进行的动作及行为。
2.时间状语:now, look,listen!at this time, these days, etc.
3.基本结构:am/is/are+doing
4.否定形式:am/is/are+not+doing.
5.一般疑问句:把be动词放于句首。
6.例句: How are you feeling today?
He is doing well in his lessons.

现在完成时态构成和用法
现在完成时态由“助动词have (has) +过去分词”构成,它可以表示过去发生或已经完成的某一动作对现在造成的影响或结果。常与一些时间状语,如:already, yet, ever, never, just, before, once, twice等连用,也可以和包括现在在内的时间状语,如these days, today, this year, so far等连用。 如:
I’ve just had my lunch. 我刚刚吃过午饭。(影响是:现在我不饿了。)
She has already posted the photos. 她已经寄走了相片。(结果是:这些相片已不在我这里了。)
现在完成时态还可以表示过去发生的动作或存在的状态,一直持续到现在,也许还将继续下去。可以和表示从过去某一时刻延续到现在的一段时间的状语连用,即for +时间段,since+时间点/从句,in the last ten years等,在这种用法中,表示持续动作或状态的动词多是延续性动词。如:
I’ve known Li Lei for three years. 我已经认识李磊有三年了。
He has been at this school for over two years. 他在这个学校已经有两年多了。
They have lived here since 2002. 自从2002年以来,他们就住在这里。
How long have you worked in this library? 你在这个图书馆里工作有多久了?
He has taught us since I came to this school. 自从我来到这所学校,他一直在教我们。
◎特征词
⑴ already(肯定句)
yet(否定句和疑问句)
never, ever(疑问句)
just (谓语动词之前) before(句末)
⑵ in the past/last few years(过去几年来)
so far = up to now/till now/by now
these days
since /ever since + 过去时间点
for + 时间段
注 意:
①since+一段时间+ago=for+时间段;
 since two weeks ago=for two weeks;
I have kept the library book for a week.
= I have kept the library book since a week ago.
②since + 时间点=for+时间段
since 2000=for 8 years
③since +从句(常用一般过去时)
The Greens have lived in Beijing since they moved to Beijing from Paris.
学习进步!
最终答案:略