逍遥右脑 2015-03-01 08:42
【—现在完成时】现在完成时通常是表示之前已发生或完成的动作，也可以表示持续到现在的动作。
11.9 现在完成时
现在完成时用来表示之前已发生或完成的动作或状态，其结果的确和现在有联系。动作或状态发生在过去但它的影响现在还存在；也可表示持续到现在的动作或状态。其构成： have (has) +过去分词。
动词一般是延续性的，如live, teach, learn, work, study, know.
举例：
I saw this film yesterday.
（强调看的动作发生过了。）
I have seen this film.
（强调对现在的影响，电影的内容已经知道了。）
Why did you get up so early?
（强调起床的动作已发生过了。）
Who hasn't handed in his paper?
（强调有卷子，可能为不公平竞争。）
She has returned from Paris.
她已从巴黎回来了。
She returned yesterday.
她是昨天回来了。
He has been in the League for three years.
(在团内的状态可延续)
He has been a League member for three years.
(是团员的状态可持续)
He joined the League three years ago.
( 三年前入团，joined为短暂行为。)
I have finished my homework now.
---Will somebody go and get Dr. White?
---He's already been sent for.
关于现在完成时上述例举了许多关于它的介绍，同学们可以在例句中寻找现在完成时的真谛。