比较+倒装考点是IS(Improving Sentence)，即改进句子题常考知识点，也是难点。题目一般考查比较对象是否一致，题目形式复杂，综合考察学生的知识点。很多学生觉得这点难理解，不好掌握。
先回忆一下倒装的知识点：倒装分为部分倒装和完全倒装，大家必须能够识别这两种倒装的信号词或提示词，比如说：完全倒装的提示词有Here, there, then等副词、out, between, among等表示运动方向和地点的副词。
一、IS题考部分倒装偏多，部分倒装的形式多样，包括：
1. 否定副词位于句首时的倒装：never, seldom, rarely, little, hardly, scarcely, no sooner, no longer, nowhere 等含有否定意义的副词若位于句首，则其后要用部分倒装。
He little realizes how important this meeting is. / Little does he realize how important this meeting is.
2.“only+状语”位于句首时的倒装：当一个状语受副词only的修饰且置于句首时，其后用部分倒装语序。
Only then did he realize that he was wrong.
3. “so…that结构”： so位于位于句首时用部分倒装
So fast does light travel that we can hardly imagine its speed.
4.“so+助动词+主语”倒装
You are young and so am I.
5. 由not only…but also引出的倒装：当not only…but also位于句首引出句子时，not only 后的句子通常用部分倒装形式。
Not only did he speak more correctly, but he spoke more easily.
6. 虚拟条件句的省略与倒装
Had you come yesterday, you would have seen him.
7.as引导的让步状语从句：必须将表语、状语或动词原形提到as前面。
Try as he would, he couldn’t open the door.
二、 比较句型。IS常考比较复合句，即比较对象是两个句子，比较的信号词有than, as, as…as, compared with等，信号词后面的句子用助动词省略，助动词时态去前面句子一致。比如：Anson realized that he loved skating more than John did.
三、 比较+倒装句型。把以上两点的融合后，句子变得复杂。做题时先通过比较句型或倒装句型的提示词找出题目中要比较的是什么事情，比较的两个对象是谁，接着判断比较对象是否一致，判断是否一致的标准是主谓一致和对象一致。以下面句子为例：
The delicious and vast menu choices contribute to the popularity of the Ethiopian restaurant, as does the authentic and quaint decor.
(A) contribute to the popularity of the Ethiopian restaurant, as does
(B) contributes to the popularity, of the Ethiopian restaurant as greatly as
(C) contributes as greatly to the popularity of the Ethiopian restaurant as do
(D) contribute to the popularity of the Ethiopian restaurant, so do
(E) contribute greatly to the popularity of the Ethiopian restaurant, as it also comes from
按照方法，先发现提示词是as引导了两个比较的句子，does提示是倒装。原题要比较的事情是contribute to the popularity of the Ethiopian restaurant, 对象有两个“delicious and vast menu choices”和“authentic and quaint decor”这么一找就可以发现，as前后两个句子时态一致，主谓一致，前后的对象都是名词，即对象一致。因此原句是对的，答案选A。BCD主谓不一致，E冗长。
