作为一种语言测试方式，
在TOEFL iBT Official Guide(托福官方指南，以下简称OG)中明确指出托福独立写作有三大考查维度：Development(展开论点)，Organization(组织文章结构)和Language Use(语言运用)。因此，除了注意作文的内容和结构外，阅卷老师同样十分注重我们在作文中表现出来的语言基本功。
托福独立写作部分对于我们写作的总体要求是consistent facility in the use of language(语言运用的和谐流畅)，给我们的具体建议是a variety of sentence structures(句子结构多样)和word choice should be appropriate(措辞贴切得体)，评分者的审查角度是lexical or grammar errors(词汇和语法错误)以及the complexity of sentence structures(句子结构的复杂程度)和the quality and complexity of your vocabulary(考生所使用的词汇的质量和复杂程度)。接下来李盛老师分别先从语法错误、措辞和句子结构三个方面来探讨备考过程中应该注意的事项：
1
lexical or grammar errors：
任何一种语言考试都强调语言表达的准确性，在2010年1月之后，ETS在独立写作部分中加入了e-rater的评分模式。电脑系统评分无疑对考生的语法词汇表达的正确性提出了更高的要求。
在2009年1月份ETS发布的Evaluating the Construct -Coverage of the e-rater? Scoring Engine中，明确指出e-Rater会关注的四大语言层面：Grammar(Proofread this, Ill-formed Verbs, Pronoun Errors, Possessive Errors, Wrong or Missing Words, Sentence Structure包括：Fragments, Run-ons, Garbled Sentences, Subject-verb agreement), Usage(Article Errors, Confused Words, Incorrect Word Forms, Faulty Comparisons, Nonstandard verbs or word forms), Mechanics(Spelling, Capitalization包括Proper Nouns和Sentence-Initial, Punctuation包括Missing Question Marks, Missing Final Punctuation, Missing Comma or Apostrophe和Hyphen Error, Fused Words, Compound Words, Duplicated Words)和Style(Repetition of Words, Inappropriate Words or Phrases, Too Many Sentences Beginning with Conjunction, Too Many Short Sentences, Too Many Long Sentences, Passive Voice)，换句话说，我们要在独立写作中避免出现以上的常见的语言表达错误，这就需要同学们在平时练习中注意语法的积累。在这里简单列举同学们在写作句子层面上经常犯的错误：
(1)粘连句(Run-ons sentence)
Run-ons sentence指一句话中包含两个或更多的意思，但这些意思之间没有用恰当的标点符号或缺乏连接词等分隔开，这往往由于写作者不熟悉英语语法表达导致。如：
Students deserve more respect they are young adults.
正确的表达可以是：
Students deserve more respect when/although they are young adults.
(2)逗号连接句(Comma splice)
Comma splice指用逗号连接两个分句。在英语中，逗号只能表示语气上的短暂停顿，不能表示两个分句间的逻辑关系，如果一句话中有几个分句，就常常使用连接词。如：
We are out of money, we decide not to eat out on the weekend.
正确的表达可以是：
We are out of money, so we decide not to eat out on the weekend.
(3)不完整句(Sentence fragment)
Sentence fragment指那些看似一句话，但实际上只是一个句子的一部分结构，往往缺少主语、谓语等基本结构，或是只有从句没有主句。如：
Driving in the city during the evening rush hour.
正确的表达可以是：
Driving in the city during the evening rush hour is dangerous.
(4)修饰语位置错误(Misplaced modifier)
Misplaced modifier指的是被放错了位置的修饰语，这种句子不仅会拗口，而且可能引起歧义。如：
At the age of five, my father started to teach me piano.
正确的表达可以是：
My father started to teach me piano when I was five.
(5)并列结构错误(Faulty parallelism)
Faulty parallelism指的是在并列结构中所使用的语法结构不一致。如：
People should be judged not only by their words, but also by what they do.
正确的表达可以是：
People should be judged not only by their words, but also by their deeds.
(6)主从句错误(Faulty subordination)
Faulty subordination 指的是本该放在主句中的内容放到了从句中，从而使本该收到强调的内容并没有受到强调。这种错误对表达的准确性上有很大的影响，但很多学生并没有意识到这个问题，这在thesis statement和主题句中尤为重要。如，在讨论面试的问题时，如果我们把thesis statement写成Interview, which can benefit the modern society a lot, is becoming increasingly popular，很明显就没有强调应该强调的内容。这句话应该写成：Interview, which is becoming increasingly popular, can benefit the modern society a lot.
2
the quality and complexity of your vocabulary
既然OG中要求word choice should be appropriate(措辞贴切得体)，如何才能做到呢?这里大多数同学都有一个误解，认为指的就是大量使用TOEFL甚至
在托福独立写作中什么样的词汇才是appropriate或者说能到的一定的quality and complexity呢?在托福的评卷中，raters一方面会考虑同学们所使用的词汇的长度和复杂度，一方面会把考试文章中所使用的词汇表达与语料库中不同等级的文章进行比较，从而大致判定我们的文字语言水平。因此，平时多去积累高分范文中的表达对于我们提升自己的语言很大的帮助。实际上各位同学能够熟练使用四级阶段的词汇便能能很好的表达意思，如我们想表达“生活中有很多这样的例子”，大多数同学第一反应是：There are many similar examples in our daily life.这句话在表达上没有错误，但是如果我们使用四级词汇中的abound写成：Life abounds with such examples. 这样的表达就会更加正式一点。
3
the complexity of sentence structures：
OG中要求做到句子结构多样，那么在保证句子表达正确性的基础上适当去变换句型就可以了。在这里很多同学又有误解，认为句子结构多样指的就是写长难句，殊不知滥用从句往往会使得语言变得啰嗦。比如说，我们想表达Mary是一个漂亮的女孩子，写成：Mary is a beautiful girl就可以了，如果偏要写成：Mary is a girl who is beautiful. 看上去句子变长了，还用上了定语从句，实际上整个句子显得累赘。我们通过对于独立写作高分范文的文本进行分析，可以总结出在高分范文中常见的句式有：
(1)并列句(包括平行结构，neither...nor...，not only...but also...等句式)
Junk food may cause a person to develop diabetes, to have heart disease, and to gain weight.
The mass media neither gives us the necessary information, nor does it tell us the truth.
We need formal education not only to gain knowledge but also learn social skills.
(2)从句(包括名词性从句、形容词性从句、副词性从句)
What kind of person you wish to become is more important than what kind of job you will have.
No one can deny the basic fact that it is impossible for average workers to master those high-technology skills easily.
A person who has an optimistic attitude toward his life can endure any hardship.
(3)插入语
After-hours study, if properly managed, holds the key to success in the 21st century.
College students, lacking social experience, are easily cheated.
(4)句子强调(包括强调句式、倒装句式、否定句式等)
Although friends definitely play a significant role in shaping teenagers' personality, it is the parents and siblings that have a far greater impact on the development of their personality traits.
Only when the heavy and frequent exposure to television is restricted or regulated will the adolescents' life, both bodily and spiritually, be guaranteed.
(5)修饰性问句
If there were no Internet, how could people get various information immediately?
Isn’t that better than worrying about who wins and who loses all the time?
(6)分词
Tourism, which is a rising industry, has become the major source of economy, playing crucial role in many Asian countries.
To be more specific, government should stage some relevant laws or regulations to severely punish the factory producing a great number of pollutants and the people littering or spitting deliberately.
当然，英语语言的使用更多的来自于同学们日常的积累。背诵单词并多读范文对于托福写作语言的准确使用有着很大的意思。