They can't have been watching the football match this time yesterday,___?

来源:百度知道 编辑:UC知道 时间:2024/05/24 07:37:18
A.must they
B.can they
C.have they
D.were they

why choose D?

因为这里can't表猜测或判断,不可能的意思,所以反义疑问词应该对问题本身提问,而不是对判断词提问。所以AB是错的。

为什么C是错的?

首先我们来把原句恢复成陈述句:
They can't have been watching the football match this time yesterday.
注意,这里的can't表示不可能。

再变成肯定句:
They were watching the football match this time yesterday.

为什么can't have been watching对应were watching?
原因是:因为是this time yesterday,所以是过去时态,如果变成can't be watching就变成现在时态了。为了表现推测的内容是过去,所以要用can't have been doing,但这里绝对不是完成时态,所以C是错误的。

问句是猜测:昨天这个时候他们不可能在看足球比赛。昨天这个时候他们在干嘛?是个过去进行时,回答的话可能是
They were watching.....或者Thet were not watching...
,所以问句的话当然要问were they?

因为情态动词+have been是对过去时的推测