可用mustn't have done表示对过去的推测吗?若可以,那这个结构与can't have done有区别吗?
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可用mustn't have done表示对过去的推测吗?若可以,那这个结构与can't have done有区别吗?
可以的话,请提供相应的信息来源.本人不甚感激~
可以的话,请提供相应的信息来源.本人不甚感激~
首先have done表示已经做过,这点就不用谈了.
can't have done 表示以前不可能做某事.
例句
---Where____Margaret have put the empty bottles?
---She________them away.They must be somewhere.
A.can;can't have thrown
B.must;must have thrown.
C.must;needn't
D.can;must throw
答案为A.第一个句子是一个疑问句而且表示可能性的推测,所以只能用情态动词can或could,第二句的答语表示对过去的推测,所以用can't have done.
请看常见的“情态动词 + have + 过去分词”的用法:
一、“must + have + 过去分词”表示对过去发生的事情或状态进行推测,语气比较坚定,通常只用于肯定句.如:
It must have rained last night,for the ground is wet.
You must have been mad to speak to the servant.
二、“can / could + have + 过去分词”表示对过去某种情况的怀疑或不确定.can和could一般用于否定句和疑问句,could的语气较can弱.如:
I didn't see her at the meeting this morning; she can't / couldn't have spoken at the meeting.
He can't have finished the work so soon.
can't have done 表示以前不可能做某事.
例句
---Where____Margaret have put the empty bottles?
---She________them away.They must be somewhere.
A.can;can't have thrown
B.must;must have thrown.
C.must;needn't
D.can;must throw
答案为A.第一个句子是一个疑问句而且表示可能性的推测,所以只能用情态动词can或could,第二句的答语表示对过去的推测,所以用can't have done.
请看常见的“情态动词 + have + 过去分词”的用法:
一、“must + have + 过去分词”表示对过去发生的事情或状态进行推测,语气比较坚定,通常只用于肯定句.如:
It must have rained last night,for the ground is wet.
You must have been mad to speak to the servant.
二、“can / could + have + 过去分词”表示对过去某种情况的怀疑或不确定.can和could一般用于否定句和疑问句,could的语气较can弱.如:
I didn't see her at the meeting this morning; she can't / couldn't have spoken at the meeting.
He can't have finished the work so soon.
可用mustn't have done表示对过去的推测吗?若可以,那这个结构与can't have done有区别吗?
should have done 可以表示对过去的推测
有mustn't have done这个结构么?表示什么?
1、shouldn't have done mustn't have done can't havedone 有什么区别
表示对过去的推测can have done,may have done 有什么不同?有的书上说有can not have
mustn't have done和can't have done的区别
could only have done表示对过去的推测,只可能...,是否等于must have done?
情态动词can't have done 和couldn't have done 有什么区别吗
can't have done与could't have done的区别
may have done 可以表示对将来的推测吗?
may have done sth 和might be 都是表示对过去的猜测 有什么区别?
高中英语could have done 只表示过去可以做而未做,可是could have been却可以表示对过去的推测