托福写作常见的语法错误都有哪些？
1. 不完整句子(Fragments)
不完整句子指的是句子当中缺少主语或谓语等，无法形成一个完整的句子。
比如：A movie that inspires deep emotions.(只有名词加定语从句，不是完整的句子)
应改为：She went to see “The Silver Star”, a movie that inspires deep emotions.
2. 不间断句子(Run-on Sentences)
不间断句子指的是用逗号来连接两个完整的句子。
比如：There is increasingly widespread reliance on electronic mail, some people still resist using it, especially those who prefer handwritten letters.
应改为：Although there is increasingly widespread reliance on electronic mail, some people still resist using it, especially those who prefer handwritten letters.(根据两句之间的关系，加入连词)
3. 主谓不一致(Subject-verb Disagreement)
主谓不一致指的是句子中主语与谓语没有保持数的一致。
比如：Many students thinks tomorrow is a holiday.
应改为：Many students think tomorrow is a holiday.
再比如：The use of cell phones during concerts are not allowed.
应改为：The use of cell phones during concerts is not allowed.
4. 可数名词“裸奔”
可数名词“裸奔”指的是可数名词之前没有冠词，也没有变为复数形式。
比如：Even expert or scholar specializing in a certain field might cover a vast spectrum of knowledge in order to succeed.
应改为：Even experts or scholars specializing in a certain field might cover a vast spectrum of knowledge in order to succeed.(可数名词变复数形式)
5. but/ however
but和however都表示转折，但是but是连词，而however是副词，也就是说however是不能来连接两个独立分句的。
比如：Printed books are limited in space, however, space is not an issue for electronic ones.
应改为：Printed books are limited in space. However, space is not an issue for electronic ones. (用句号将原句分成两个独立分句)
6. therefore
therefore也是副词，表示“因此”，它也不能连接两个独立分句。
比如：Pupils always look to their teacher for guidance, therefore the influence that a teacher has could never be underestimated.
应改为：Pupils always look to their teacher for guidance; therefore the influence that a teacher has could never be underestimated.(用分号将两个独立分句连接起来)
或者：Pupils always look to their teacher for guidance, and therefore the influence that a teacher has could never be underestimated.(用and将两个独立分句连接起来)
7. there be句型
there be句型中be动词本身已经是谓语部分，不能再出现谓语动词。
比如：There are many people prefer to wear clothes made of natural fibers.
应改为：There are many people who prefer to wear clothes made of natural fibers.(后面prefer to改放到定语从句里)
8. 比较对象的对等
在比较结构中，注意前后比较事物要对等。常用that和those来指代“比较结构”里先前提到的名词。
比如：The merits of serious movies far outweigh funny movies.
应改为：The merits of serious movies far outweigh those of funny movies.(those指代的是前半句的比较对象merits)
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