语法图解
探究发现
①People have been enjoying the benefits of cycling in Amsterdam for years.
②Many people around the world have been enjoying city centre streets without cars for many years.
③He has been fighting with a friend.
④I have been looking for a job for three months.
⑤I have been writing letters all this evening and I've just finished them.
⑥You haven't been doing your homework those days.
⑦Too much has been happening today.
[我的发现]
(1)现在完成进行时态的构成：肯定形式have/has_been_doing(句①～⑤)；否定形式have/has_not_been_doing(句⑥)。
(2)现在完成进行时表示动作开始于过去，并一直持续到现在，动作可能仍在进行，也可能刚刚结束(句⑤)。
(3)现在完成进行时也可以带有某种感情色彩(句⑦)。
