has been doing 是现在完成进行时
一、结构
I/ we/ you/ they have been doing sth
he/ she/ it has been doing sth
二、主要用法
表示从过去某时开始一直持续到现在的动作,并且还将持续下去.eg He has been working here for 2 years.
表示在说话时刻之前刚刚结束的动作.eg.I have been waiting for you for 2 hours.我已经等你两个钟头了.（动作不再继续下去）
现在完成进行时需注意的是其与现在完成时的区别