高考英语一轮复习——情态动词完成时态的用法

“情态动词+have done”用法归纳 情态动词+have done 用法 例句 must have done 表示主观上对过去已经发生的行为进行推测，意为“想必，准是，一定做了某事” ①She must have gone through a lot. ②He must have visited the White House during his stay in the United States. may have done might have done ① 表示对过去已发生行为的推测，意为“也许/或许已经（没有）……” ② 一般用于肯定句或否定句中，不用于疑问句 ③ 用might则表示语气更加不肯定 ①You may have learnt the news. ②He may not have heard his name called. ③Sorry I’m late. I might have turned off the alarm clock and gone back to sleep again. might have done ① 表示“本来可能……，但实际上没有发生的事情”即，推测过去有可能发生但已确知并为发生的事情may have done 没有此用法 ② 另外，还可以表示“本来应该或可以做某事”之意，含有轻微的责备语气；有时也表劝告 ①You should not swim in that sea; you might have been eaten by a shark. ② He might have given him more help, thought he was busy. can…have done cannot have done ① 只用在否定句和疑问句中 1 表示对过去发生的行为的怀疑和不肯定 ③ can换成could时语气委婉 ① Where can she have gone? ② Could he have done such a foolish thing? ③ The boy can’t have finished reading the book so soon because it is difficult even to an adult. could have