19.8 比较while, when, as 1）as, when 引导短暂性动作的动词。 Just as / Just when / When I stopped my car, a man came up to me. 2）当从句的动作发生于主句动作之前，只能用when 引导这个从句，不可用as 或 while。 When you have finish…...

19.3 原因状语从句 比较：because, since, as和for 1） because语势最强，用来说明人所不知的原因，回答why提出的问题。当原因是显而易见的或已为人们所知，就用as或 since。 I didn't go, because I was afraid. Since /As the weather is so bad…...

14.6 as, though 引导的倒装句 as / though引导的让步从句必须将表语或状语提前 （形容词, 副词, 分词, 实义动词提前）。注意： 1) 句首名词不能带任何冠词。 2) 句首是实义动词, 其他助动词放在主语后。如果实义动词有宾语和状语, 随实义动词…...

7.7 不定式作状语 1）目的状语 To… only to (仅仅为了), in order to, so as to, so(such)… as to… (如此……以便……) He ran so fast as to catch the first bus. 他飞快地跑以便赶上第一班车。 I come here only to say good-bye to you. 我来…...

19.10 表示"一…就…"的结构 hardly/scarcely…when/before, no sooner…than 和as soon as都可以表示"一…就…"的意思，例： I had hardly / scarcely got home when it began to rain. I had no sooner got home than it began to rain. As soon as…...

19.5 结果状语从句 结果状语从句常由so… that 或 such…that引导，掌握这两个句型，首先要了解so 和 such与其后的词的搭配规律。比较：so和 such 其规律由so与such的不同词性决定。such 是形容词，修饰名词或名词词组，so 是副词，只能修饰形容词或副…...

17.5 否定转移 1) 将think, believe, suppose, expect, fancy, imagine等动词后面宾语从句的否定词转移到主句中，即主句的谓语动词用否定式，而从句的谓...

11.15 过去完成时 1） 概念：表示过去的过去----|-------|-----|----其构成是had +过去分词构成。那时以前 那时 现在 2） 用法 a. 在told, said, knew, heard, thought等动词后的宾语从句。 She said (that) she had never been to Paris. b.…...

2.5 冠词位置 1) 不定冠词位置 不定冠词常位于名词或名词修饰语前。注意： a. 位于下列形容词之后： such，what，many，half， I have never seen such an animal. Many a man is fit for the job. b. 当名词前的形容词被副词as, so, too, how, …...

19.7 让步状语从句 though, although 注意： 当有though, although时，后面的从句不能有but，但是 though 和yet可连用 Although it's raining, they are still working in the field. 虽然在下雨，但他们仍在地里干活。 He is very old, but he still…...