have sth doing是什么时态

　　现在完成进行时基本句型

　　肯定式第一人称have been doing sth.

　　疑问式：Have+第一人称+been doing sth.

　　简略回答：Yes，第一人称 have.No，第一人称 haven't.

　　肯定式：第三人称+has been doing sth.

　　疑问式：Has+第三人称been doing sth.

　　简略回答：Yes，第三人称has.No，第三人称hasn't.

　　1）表示一个在过去开始而在最近刚刚结束的行动，如：

　　Ann is very tired. She has been working hard.

　　Why are your clothes so dirty? What have you been doing?

　　2)表示一个从过去开始但仍在进行的行动，如：

　　It has been raining for two hours.(现在还在下)

　　Jack has been feeling very well recently.

　　3)表示一个从过去开始延续到现在，可以包括现在在内的一个阶段内，重复发生的行动，如：

　　She has been playing tennis since she was eight.

　　4)现在完成时强调动作行为的结果、影响，而现在完成进行时只强调动作行为本身，如：

　　Tom’s hands are very dirty. He has been repairing the car.

　　The car is going again now. Tom has repaired it.

　　标志：1.句中常有延续性动词，2.时间点前有since。