现在进行时和现在完成进行时区分:
区分 have done have been doing,我们需要从两个方面来讨论:
一、完成时态和完成进行时态本身意义的差别;
二、要结合动词的不同延续特点    .首先我们来看两种时态的意义差别
两者根本区别是:    完成进行时强调动作持续的过程铲形币    (emphasis on duration), 完成时强调动作的
结果或成就  (emphasis on achievement).具体来讲 ,现在完成进行时    have been doing 强调的是在
一段时期内某项活动的持续性    ,强调的是动作本身    .现在完成时    have done 则是强调动作产生
的结果或取得的成就    ,而不是动作本身    .二者的这种区别我们从下面的这些例句可以很好地领
悟到: (2) a. My hands are very dirty. I ve been painting the house. b. I have painted the house green. The house was white, but now it s green.
思维分析:
a have been painting 表示 painting 动作一直在持续  ,活动还没有结束  ,所以才有  my hands
are very dirty 这样的现状 . a 意思是“我的手很脏    ,我现在一直在给房间刷漆”    .
b 约分口诀 have painted 表示 painted 动作已经结束  ,而且动作导致的结果是    the house was white, but
now it s green 房间现在是绿的了    .
现在完成时表示动作业已完成    , 而完成进行时却不一定如此

I ve made a cake. 我做了一个蛋糕    .(已做好)
I ve been making a cake. 我一直在做一个蛋糕    . (不一定做好了
She s painted a picture. 她画了一幅画  .(已画好)
She s been painting a picture.  她在画一幅画  .(可能还没画好   
强调时间长度用完成进行时比较好:    Ive been coughing all night.
我咳了一整夜
.(比
I ve毒爱

coughed all night.    更能强调咳得久)
All the time she s been sitting there in silence.    她一直静坐在那里    .
写观后感All these years we ve been trying to get in touch with him.    这些年来我们一直在设法和他联系    .
许多静态动词都只能用于完成时而不能用于完成进行时:
I ve known that for a long time.    这事我已经知道很久了    .
The strike has lasted six months.  这次罢工已经持续了    6 个月 .
Nobody has seen him since last week.  从上周起就没人见到过他    .
raise in salary all the time.    他一直盼着加薪    .
但当意思发生转变时也可能用于完成进行时:
I ve been thinking of doing so for a long time.    我好久以来一直想这样做
.Tom has been seeing about a work permit for you.    汤姆一直在设法帮你取得工作许可证    .


有少数动词用两种时态都可以
,意思差别不大
,如:

They have been working very well this term.
这学期他们学习很好
急性痛风吃什么药
稿件大全. They have worked very well