英语Essay写作中国留学生需要掌握的一个技能，一篇文笔简洁优雅的Essay对于提高分数会有很大帮助。但目前的情况是，很多人并没有受过专门的学术Essay写作训练，在写Essay时经常会出现各种各样的语言问题。今天的文章主要谈一谈英文Essay写作中的常见错误，希望对你有所帮助。
总体来说，学术Essay写作跟其他类型的英文写作一样，都要遵循清晰简洁的原则，这一原则主要有以下体现：
1.主动语态与被动语态
英文中的主动语态特点是简洁有力，动作发出者明确，而被动语态特点是较为冗长且有时候看不出动作的发出者是谁(比如Measures should be taken to address this issue.从这个句子里面我们无法确定应该是谁采取行动)。在Essay写作中，很多地方都要明确指出动作的发出主体(比如实验是谁操作的，数据是谁测量的)，且语言要尽可能简洁。因此，Essay写作中应该多使用主动语态。
类似下面的句子：
(1)Consideration of whether countries work well on cross-border issues such as immigration was undertaken by Raul(2007).
(2)Identification of poor food,bad housing,inadequate hygiene,and large families as the major causes of poverty was made by Jones(2005).
应该改为：
(1)Raul(2007)considered whether or not countries work well on cross-border issues such as immigration.
(2)Jones(2005)identified poor food,bad housing,inadequate hygiene,and large families as the major causes of poverty.
那么有没有需要使用被动语态的情况呢?更多写作技巧：report.lxws.net
有。当我们无法明确动作的发出者，或者需要强调动作本身而不是强调动作发出者的时候，就可以使用被动语态。比如：
(1)Up to 90%of the energy in light bulbs is wasted in the form of heat.
(2)The first edition of Freud’s earliest writings on dreams was published in 1899.
第一个句子里面waste这个动作的发出者无法明确(也没必要明确)，第二个句子里面谁出版了Freud的作品并不重要，因此也没有必要使用主动语态来说明出版商是谁。
2.比较句
我们知道，在英语比较句中有时候可以省略被比较主体后面的动词，比如：
On average,men are taller than women are.
可以省略为：
On average,men are taller than women.
但这种省略有时候会造成歧义，举个例子：
Women prefer friendly doctors more than men do.
如果我们将do省略的话，会变成：
Women prefer friendly doctors more than men.
此时句子会产生歧义，因为它可以有两种不同的理解：
Women prefer friendly doctors more than men prefer friendly doctors.女人比男人更喜欢友善的医生。
Women prefer friendly doctors more than they prefer men.比起喜欢男人，女人更喜欢友善的医生。
为了避免歧义，我们应该保持比较句型形式上的完整。类似这样的句子：
(1)The finance department focuses on profits more than the human resources department.
(2)Country A funds high-tech innovation more than Country B.
应该改为：
(1)The finance department focuses on profits more than the human resources department does.
(2)Country A funds high-tech innovation more than Country B does.
3.使用动词而不是名词
英语中动词通常要比名词要简洁，因为名词本身看不出动作，经常需要额外的动词去修饰它。比如要表达“做出贡献”，使用名词形式我们要说make contributions to，但如果用动词只需要说contribute，在Essay写作中能使用动词的场合尽量使用动词，以保持文章的简洁。类似下面这样的句子：
(1)Enumeration of three reasons why the English language has become so important was made by Thompson(2006).
(2)Discussion of the challenges and strategies for facilitation and promotion of ERP was performed by Smith(2007).
需要改为：
(1)Thompson(2006)enumerated three reasons why the English language has become so important.
(2)Smith(2007)discussed the challenges and strategies for facilitatingandpromoting ERP.
4.减少there be句型以及it的使用
There be句型可能是中国学生最熟悉的句型之一，但大部分there be句型都不够简洁，可以使用其他形式来替换。比如：
There is a necessity for a semi-structured approach to be chosen.
可以改为更加简洁的版本：
A semi-structured approach must be chosen.
又比如：
There is a need for implementation of the policy on a larger scale by the president of the association.
可以改为：
The association president must implement the policy on a larger scale.
对于形式主语it，我们也可以进行精简，比如：
(1)It is essential that the model be revised.
(2)It was important for the government to intervene.
可以改为：
(1)The model must be revised.
(2)The government must intervene.
5.Misplaced modifiers
Misplaced modifiers是指将修饰语放在错误的地方，从而产生歧义的现象。举个例子：
I was told that I would be awarded the scholarship by my professor.
这句话因为by my professor这一修饰语放置不当而产生了歧义。它可以理解为“我被我的教授告知我会获得奖学金”，也可以理解为“我被告知我的教授会授予我奖学金”。避免歧义的方法是调整by my professor的位置，比如：
I was told by my professor that I would be awarded the scholarship.
类似的例子还有：
A team led by Dr.Craig Smith from the University of Hawaii at Manoa found the crabs using a remotely operated submersible.
这句话同样有歧义，因为using a remotely operated submersible可以理解为螃蟹发出的动作，也可以理解为研究团队发出的动作。为了避免歧义，句子可以改为：
A team led by Dr.Craig Smith from the University of Hawaii at Manoa used a remotely operated submersible to find the crabs.
6.慎用代名词
我们有时候会用代名词来指代前面提到的名词或是句子成分，但它有个缺点：读者有时候很难确定代名词究竟指代哪一部分。因此使用代名词时一定要谨慎，必要时可以对代名词进行替换。比如：
A case study approach was chosen;this allowed a closer observation of a single specimen.
句子中this可能指代a case study approach，也可能指代a case study approach was chosen这一整句话，为了使句意清晰，我们可以将句子改为：
A case study approach was chosen to allow a closer observation of a single specimen.
又比如：
X substantially alters Y.This suggests that Y can be modified using the proposed model.
句子可以改为更清晰的版本：
X substantially alters Y.This finding suggests that Y can be modified using the proposed model.
7.避免使用可能会造成性别歧视的代名词
在使用he,she,his,her,him这类代名词时，应避免出现只偏袒一方情况，举个例子：
When a politician campaigns for office,he must spend considerable funds to compete with his opponents.
这里代名词只提及到了男性一方，为了避免出现性别歧视，我们可以使用名词和代词的复数形式：
When politicians campaign for office,they must spend considerable funds to compete with their opponents.
或者将句子中的代名词去掉：
A politician who campaigns for office must spend considerable funds to compete with opponents.
同时，在使用一些名词的时候也要注意性别问题，比如要表达“人类”，用humankind会比用mankind好一点，因为mankind带有一定的性别色彩，一些人会质疑为什么只有mankind而没有womankind，而使用humankind会显得公平很多。
8.逗号问题
虽然逗号看起来是小问题，但还是有不少人会用错。这里提一个常见的问题：当连词后面的句子不完整时，连词前面不能用逗号。举个例子：
I knew the price of IBM stock would increase after it entered the home computer market,but had no idea that the price would skyrocket.
连词but后面的部分had no idea that the price would skyrocket不是一个完整的句子，因此but之前不能加逗号。也就是说，上面的写法是错误的。
正确的写法应该是：
I knew the price of IBM stock would increase after it entered the home computer market but had no idea that the price would skyrocket.
另外，如果连词后面的部分是一个完整的句子，则建议在连词前面加逗号，比如：
I knew the price of IBM stock would increase after it entered the home computer market,but I had no idea that the price would skyrocket.
不推荐下面这种写法：
I knew the price of IBM stock would increase after it entered the home computer market but I had no idea that the price would skyrocket.
除了上面提到的这几点之外，常见的Essay写作问题还有滥用大词、冗余以及冠词使用错误等。