1) must用在肯定句中表示较有把握的推测,意为"一定"。 2) must表对现在的状态或现在正发生的事情的推测时, must 后面通常接系动词be 的原形或行为动词的进行式。 You have worked hard all day.You must be tired. 你辛苦干一整天,一定累了。(对现在情况的推测判断) He must be working in his office. 他一定在办公室工作呢。 比较: He must be staying there. 他现在肯定呆在那里。 He must stay there。 他必须呆在那。 3) must 表示对已发生的事情的推测时,must 要接完成式。 I didn't hear the phone. I must have been asleep. 我刚才没有听到电话,我想必是睡着了。 4) must表示对过去某时正发生的事情的推测,must 后面要接不定式的完成进行式。 ---Why didn't you answer my phone call? ---Well, I must have been sleeping, so I didn't hear it。 5) 否定推测用can't。 If Tom didn't leave here until five o'clock, he can't be home yet. 如果汤姆五点才离开这儿,他此时一定还未到家。 (责任编辑:admin) |