2014年公共英语四级考试问题解答(9)

2013-10-25 22:12:39来源：百度文库

　　考生问题：

　　could等于was able to吗?

　　在学了情态动词后，觉得对它的用法好像都明白了，但我最近碰到一个问题，感到事实远非如此。下面就是我遇到的一个问题，请问，正确答案是was able to, 那么选could为什么不可以?

　　He didn’t agree with me at first, but I ________ persuade him to sign the agreement later.

　　A. could B. might C. should D. was able to

　　名师解答：

　　在本句中might 和should这两个选项意思讲不通。实际上就是考查could和was able to 的区别。could表示“(过去)有能力做某事”，was able to 除了这层意思外，还有一个重要的意思，就是：“设法做了某事(managed to do sth.)”，“成功地做了某事(succeeded in doing sth.)”。如果只表达“有能力做某事”这层意思，那么这两个可以互换，而意思保持不变，例如：

　　He was very strong and he could (was able to) lift that big stone. 他很强壮，他能够举起那块大石头(意思是他有这个能力)。

　　但是，如果是第二层意思，那么，只能用was able to，不能用could，例如：

　　At last，he was able to solve the problem.(正)

　　At last he could solve the problem.(误)

　　Only when the war was over was he able to get happily back to work.(正)

　　Only when the war was over could he get happily back to work.(误)

　　但是，当句子是否定意思时，这两个意思完全相同：

　　I couldn’t persuade him to sign the agreement.= I wasn’t able to persuade him to sign the agreement.

　　相关知识：

　　1.She could play the violin when she was five.

　　她五岁时便能拉小提琴了。

　　2.(用于虚拟语气,表示与事实相反的设想)能,可以

　　I wish I could go to France.

　　但愿我能去法国。

　　I would go if I could.

　　能去我就去。

　　3.I was able to achieve this because, all year long, I had the daily running habit and daily accountability habit.

　　我能够做到这一点是因为一年之内我养成了每日跑步和培养毅力的习惯。

　　4.Anyone was able to create a website or an online shop, which could be reached from anywhere in the world using a simple piece of software called a browser, without asking anyone else for permission.

　　任何人可以建立一个网站或在线商店,这个站点又可以由世界上的任何地方登录 -仅仅使用一个叫浏览器的软件, 还无须获得任何人的准许.

本文关键字: 2014年公共英语四级考试