虚拟语气:need不必做和本不必做
文章作者 100test 发表时间 2008:03:15 10:07:12
来源 100Test.Com百考试题网
didn t need to do表示过去不必做某事, 事实上也没做。
needn t have done表示过去不必做某事, 但事实上做了。例如:
John went to the station with the car to meet Mary, so she didn t need to walk back home.
约翰开车去车站接玛丽,所以她不必步行回家了。
John went to the station with the car to meet Mary, so she needn t have walked back home.
约翰开车去车站接玛丽,所以她本不必步行回家了。 (Mary步行回家了,没有遇上John的车。)
典型例题
There was plenty of time. She ___.
A. mustn t have hurried B. couldn t have hurried C. must not hurry D. needn t have hurried
答案D.needn t have done. 意为"本不必",即已经做了某事,而时实际上不必要。
Mustn t have done 用法不正确,对过去发生的事情进行否定性推断应为couldn t have done, "不可能已经". must not do 不可以(用于一般现在时)。