2.The letter could have got lost in the post.这封信可能是在邮递中丢失了。(说话人并不确切知道那封信是否在邮递中丢失)
由于这个结构能表示两种不同的含义,所以有些句子,脱离上下文,可能会产生歧义:
He could have sent a message.
a)他可能送了个信儿来。(说话人并不知道他事实上是否送来了信儿)
b)他本可以送个信儿来的。(说话人确切知道他并没有送信儿来)
同样,上面的试题可能含有两种不同的含义:
a)……你本来可以同巴巴拉住在一起的。(暗含的意思是:你本不必住旅馆的)
b)……你可能同巴巴拉住在一起了。(说话人的一种推测)
couldn't have done /mustn't have done
[问](1)-There were already five people in
the car but they managed to take me as well.
-It ______a comfortable journey.
A.can't be B.shouldn't be C.mustn't have been D.couldn't have been(全国高考, 95-15)
答案为D。能否选C呢?
[答]我国出版的许多英语语法书和英语试题都特别强调:must用于表示"推测"(一定、必定)时,其否定形式只能是can't,而绝不是must not(mustn't)。例如,She must be asleep.=She can't be awake.(《实用英语语法》),情况是否真的如此呢?让我们先看两个反例: