答:英语助动词的用法:
1. 助动词be(am, is, are, was, were, being, been)的用法
(1) be后跟现在分词构成进行时态。 Who is playing the violin? 谁在拉小提琴? She was reading a book then.那时她正在读书。
(2)be后跟过去分词构成被动语态。 He was asked to do the work.有人要他干这件工作。 You are invited to attend the meetintg.有人邀请你参加会议。
(3)be 后跟不定式作谓语,有如下几种情况:①表示计划、安排将要发生的事。 Who are we to meet? 我们要见谁呀? I'm to have supper with John this afternoon.今天下午我要与约翰一起吃晚饭。
②表示指示、命令,否定式表禁止。 You are to see the headmaster today.今天你必须去见校长。 You are not to enter the room without permission.未经允许你不能进入房间。
③表示义务、责任等,同should。 You are to be back before 5.你得在5点钟以前回来。 What is to be done? 该干什么。
④表示可能性,与情态动词may, can同义。 Such books are to be found in any library.这种书任何图书馆都有。 Not a sound was to be heard.一点声响也没有。
⑤表示后来发生的事,可以用来表示命运或注定 They say good-bye, little knowing that they were never to meet again.他们告别了,没想到再也不能相见了。 He was to regret the decision.他有一天会后悔做出这一决定的。
⑥用于习语 Where am I to go? 我该向何处去? What am I to do? 我该怎么办?
