1. 情态动词表推测

　　(1)对现在、将来情况的推测，用情态动词+动词原形

　　对现在、将来情况的肯定推测：must+动词原形

　　对现在、将来情况的否定推测：can’t +动词原形

　　对现在、将来情况的可能推测：may/might +动词原形

　　例句：What is he doing?

　　He must be sleeping./He can’t be reading./ He may/might be reading but I’m not sure.

　　(2)对过去情况的推测，用情态动词+have done sth.

　　对过去情况的肯定推测：must+have done sth.

　　对过去情况的否定推测：can’t +have done sth.

　　对过去情况的可能推测：may/might +have done sth.

　　例句：It must / may / might / have rained last night. The ground is wet.

　　The door is locked. He cannot / may ( might ) not have been at home.

　　2. 部分倒装：否定词前置

　　(1)hardly/scarcely…when…

　　例句：Hardly had she gone out when a student came to visit her.

　　她刚一出门，一个学生就来拜访她。

　　(2)no sooner…than…

　　例句：No sooner had the game begun than it began to rain heavily.

　　比赛刚一开始就下起了雨。

　　3. 动词 ing 形式作独立主格结构：逻辑主语和主句主语不一致时采用。

　　例句：Time permitting, we will go for a picnic tomorrow. (=f time permits, we will go for a

　　picnic tomorrow.) 如果时间允许，我们明天会去野餐。

　　4. so...as to 结构：表示“如此......以至于......”。

　　例句：The girl was so excited as to shout herself hoarse. 那个女孩兴奋得喊哑了嗓子。

　　5. even if 引导的让步状语从句：“即使”。

　　例句： Even if we achieve great success in our work, we should not be proud.

　　即使我们在工作中取得了巨大成绩，也不应该自满。