无论在大作文还是在小作文中，对于语法的评分要求之一就是句式的多样化。而对于基础较薄弱的学生而言，这一要求很难达到，因此在语法方面表达单一，无法拿到高分。一下总结了句式变化其中一种方法－主语对氧化。

　　1.入门级别的主语

　　最简单的名词充当主语

　　1) Young people should be encouraged to broaden their horizons.

　　2) The main concern is about the type of computer activities that attract children.

　　无论是主谓宾还是主系表结构，最主要充当主语的成分为名词或名词短语，也就是作文中的讨论对象或描述主体。除此之外，主语被或长或短地修饰一下：

　　1) Sports professionals in many countries have become stars and celebrities. （介词短语修饰主语）

　　2) The amount of money they are able to earn in a short time seems to be unjustified. （定语从句修饰主语）

　　3) A person killing for self-defense cannot be compared with a serial killer. （分词短语修饰主语）

　　4) The proportion of money spent on food remained the highest throughout the period. 分词短语修饰主语）

　　当注意中包含动作时，把动词变成非谓语动词形式：

　　1) Smoking is harmful to people's health.

　　2)Eating too much fast food is considered to be a leading cause of obesity, hypertension and heart disease.

　　2.中文里不存在的主语----It （形式主语）

　　1) It is important to use a condom when having sex.

　　2) It is quite common for young people to have a break from studying after graduating from high school.

　　3.用一个完整的句子做主语－主语从句

　　1) Students study abroad can reap a number of benefits. （典型错误）

　　2) Parents give children pocket money is a good decision. （典型错误）

　　3) Government spends a lot of money on space exploration will lead to many problems. （典型错误）

　　要解决这三个错误的句子只需要好好研究主语从句的连接词！

　　4.用疑问词充当连接词做主语

　　1) Whether children should be given pocket money has long been a controversial issue.

　　2) Whether people should retire at 60 depends on their physical conditions.

　　3) What governments ought to do is to impose heavy tax on calorie-rich food.

　　4) What parents do has a great influence on their children