情态动词must, can, could, may, might 表推测的用法: 1
用于肯定的推测:must > can > could > may > might 1)其中must 语气最强最肯定,只用于肯定句,意为“一定,准是,必然会”
You haven’t eaten anything since this morning,you must be hungry
2) can 次之一般表示理论上可能性,但实际未必会发生
意为“可能”
Even experienced teachers can make mistakes
3) could 再次之,意为“可能” My book has disappeared
Who could have taken it
4) may / might 语气最弱,表示无把握的推测,意为“可能,或许”
(might 比 may 更加不肯定,更无把握)
例如: He may/might be writing a letter now, but I’m not sure
用于否定的推测can’t >couldn’t > may not > might not 1)can’t 用于否定推测,是语气最强的否定推测,意为“不可能,一定不(是)”
He can’t her here because she is in hospital
2)couldn’t 比can’t 语气弱,表示某事不可能真实,但自己也不是很肯定
It couldn’t possibly be Tom
He should be at school now
may not/ might not 表示否定推测时,表示(无把握的)否定推测,意为“可能/或许不”
例如: It’ still early
He may/might not