我们在写英语句子的时候，常常会犯一些相同的错误。下面这十个错误后面，都附有正确答案，以及详细的解说。
Incomplete Sentence - Sentence Fragment
句子不完整——残缺句
One common mistake many students make is the use of incomplete sentences. Each sentence in English must contain at least a subject and a verb, and should be an independent clause. Examples of incomplete sentences without a subject or a verb might include an instruction or a prepositional phrase.
许多学生都会犯一个常见的错误，就是写出来的句子不完整。英语中，每个句子都必须至少有一个主语，一个动词，并单独成句。没有主语或动词的残缺句子可能就只有表示指令的句子或者介词短语了。
For example:
例如：
Through the door.
穿过大门。
In the other room.
在另一个房间。
Over there.
在那里。
These are phrases we may use in spoken English, but that should not be used in written English as they are incomplete.
在英语口语中，你可能会用到这些短语，但是因为它们毕竟不是完整的英语句子，所以在书面语言中，我们一般不会使用。
Sentence fragments caused by dependent clauses used without an independent clause are more common. Remember that subordinating conjunctions introduce dependent clauses. In other words, if you use a subordinating clause beginning with a word such as 'because, though, if, etc.' there must be an independent clause to complete the thought. This mistake is often made on tests asking a question with 'Why'.
由于缺乏独立分句的从属子句导致的句子残缺很常见。记住，从属连词引出了从属子句。也就是说，如果你用一些词语来引出从句，例如because，though，if等等，就必须要有一个独立分句来使句子完整。我们在考试中，使用why来提出问题时，经常会犯这样的错误。
For example, the sentences:
例如，下面这个句子：
Because Tom is the boss.
因为汤姆就是老板。
Since he left work early without permission.
自从他不经允许就早退。
We might answer the question: "Why did he lose his job?" However, these are sentence fragments. The correct answer would be:
我们可能会问：“他为什么丢掉工作?”但是，这些句子都是不完整的。正确用法应该是：
He lost his job because Tom is the boss.
因为汤姆就是老板，所以他丢掉了工作。
He lost his job since he left work early without permission.
他因为不经允许就早退而丢掉了工作。
Other examples of incomplete sentences introduced by subordinating clauses include:
其他关于从属子句的残缺句还包括下面内容：
Even though he needs help.
虽然他需要帮助
If they study enough.
如果他们好好学习
As they had invested in the company.
因为他们投资了这家公司
Run-on Sentences
句子不连贯
Run-on sentences are sentences that:
不连贯句子指的是：
1) are not connected by appropriate linking language such as conjunctions
缺乏合适的连接词，例如连词。
2) use too many clauses rather than using periods and linking language such as conjunctive adverbs
使用过多的从句，而非句号和连接语，例如连接副词
The first type leaves out a word - usually a conjunction - that is required to connect a dependent and independent clause. For example:
第一种是漏掉了一个词——通常是连接词——用于连接非独立子句和独立子句。
The students did well on the test they didn't study very much.
学生们考得很好他们没有下多少功夫。
Anna needs a new car she spent the weekend visiting car dealerships.
安娜想买辆新车她整个周末都在约见代理商。
The first sentence should use either a conjunction 'but', or 'yet' or a subordinating conjunction 'although, even though, or though' to connect the sentence. In the second sentence, the conjunction 'so' or the subordinating conjunction 'since, as, or because' would connect the two clauses.
第一句话要么应该加上一个连词but，要么加上yet，或者一个从属连词although, even though或though来连接前后两句。
The students did well, yet they didn't study very much.
学生们考得很好，但他们并没有下多少功夫。
Anna spent the weekend visiting car dealerships since she needs a new car.
因为想买辆新车，安娜整个周末都在约见代理商。
Another common run on sentence occurs when using too many clauses. This often occurs using the word 'and'.
另一种句子不连贯发生在使用太多从句的时候。常常是由于and一词导致。
We went to the store and bought some fruit, and we went to the mall to get some clothes, and we had lunch at McDonald's, and we visited some friends.
我们去商店买了一些水果，去购物商城买了一些衣服，在麦当劳吃的午饭，又见了一些朋友。
The continuous chain of clauses using 'and' should be avoided. In general, do not write sentences that contain more than three clauses to ensure that your sentences do not become run-on sentences.
我们应该避免使用and来连接一大串的从句。一般来说，从句不要超过三个，以确保句子的连贯性。
Duplicate Subjects
两个主语
Sometimes students use a pronoun as a duplicate subject.
有时候，学生们会将代词作为第二个主语。
Remember that each clause takes only one sentence. If you have mentioned the subject of a sentence by name, there is no need to repeat with a pronoun.
记住，每个从句只需要一句话。如果之前你已经提到主语的名字，就不需要再用代词重复了。
Example 1:
例一：
Tom lives in Los Angeles.
汤姆住在洛杉矶。
NOT
而不是
Tom, he lives in Lost Angeles.
汤姆，他住在旧金山。
Example 2:
例二：
The students come from Vietnam.
学生们来自越南。
NOT
而不是
The students they come from Vietnam.
学生们他们来自越南。
Incorrect Tense
时态错误
Tense usage is a common mistake in student writing. Make sure that the tense used corresponds to the situation. In other words, if you are speaking about something that happened in the past do not use include a tense that refers to the present. For example:
时态错误在学生写作中很常见。你要确保时态与事情发生的情况一致。也就是说，如果你要表达的是发生在过去的事，就不要使用现在时态。例如：
They fly to visit their parents in Toronto last week.
上周他们坐飞机去看望父母。
Alex bought a new car and drives it to her home in Los Angeles.
亚历克斯买了一辆新车，并把它开进了洛杉矶的家。
Incorrect Verb Form
动词形式错误
Another common mistake is the use of an incorrect verb form when combining with another verb. Certain verbs in English take the infinitive and others take the gerund (ing form).
另一个常见的错误就是在与其他动词连用时，动词形式的错误。英语中的动词既有不定式形式，又有动名词形式。
It's important to learn these verb combinations. Also, when using the verb as a noun, use the gerund form of the verb.
学习这些动词的连用很重要。当动词作为名词使用时，就要使用动名词形式。
He hopes finding a new job. / Correct -> He hopes to find a new job.
他想找一个新工作。
Peter avoided to invest in the project. / Correct -> Peter avoided investing in the project.
皮特没有在这个项目上投资。
Parallel Verb Form
动词复数形式
A related issue is the use of parallel verb forms when using a list of verbs. If you are writing in the present continuous tense, use the 'ing' form in your list. If you are using the present perfect, use the past participle, etc.
在使用多个动词时，有一个问题就是动词复数形式的使用。如果你是在用现在进行时进行写作，就应该使用动词ing形式。如果你使用的是现在完成时，就应该使用过去分词形式。
She enjoys watching TV, play tennis, and cook. / Correct -> She enjoys watching TV, playing tennis, and cooking.
她喜欢看电视，打网球和烹饪。
I've lived in Italy, working in Germany and study in New York. / Correct -> I've lived in Italy, worked in Germany, and studied in New York.
我住在意大利，在德国工作，在纽约读书。
Use of Time Clauses
时间从句的使用
Time clauses are introduced by the time words 'when', 'before', 'after' and so on. When speaking about the present or future use the present simple tense in time clauses. If using a past tense, we usually use the past simple in a time clause.
时间从句由时间词语引导，例如when，before，after等等。当我们表达现在或将来的事时，可以使用一般现在时的时间从句。如果使用过去时态，通常会使用过去时的时间从句。
We'll visit you when we will come next week. / Correct -> We'll visit you when we come next week.
下周我们会来看你。
She cooked dinner after he was arriving. / Correct -> She cooked dinner after he arrived.
他到了之后，她才开始煮饭。
Subject - Verb Agreement
主谓一致
Another common mistake is to use incorrect subject - verb agreement. The most common of these mistakes is the missing 's' in the present simple tense. However, there are other types of mistakes. Always look for these mistakes in the helping verb.
另一个常见的错误就是主谓不一致。最常见的就是一般现在时中漏掉了-s。但是，还有其他类型的错误。这些错误常发生在助动词的使用上。
Tom play guitar in a band. / Correct -> Tom plays guitar in a band.
汤姆在乐队里是弹吉他的。
They was sleeping when she telephoned. / Correct -> They were sleeping when she telephoned.
他打电话过来时，他们都睡着了。
Pronoun Agreement
代词一致
Pronoun agreement mistakes take place when using a pronoun to replace a proper noun. Often this mistake is a mistake of use of a singular form rather than a plural or vice versa. However, pronoun agreement mistakes can occur in object or possessive pronouns, as well as in subject pronouns.
代词不一致发生在用代词来替代专有名词的情况下。通常是使用了单复数形式的错误使用。但是，代词不一致也会发生在宾语或物主代词，和主格代名词上。
Tom works at a company in Hamburg. He loves his job. / Correct -> Tom works at a company in Hamburg. He loves his job.
汤姆在汉堡一家公司工作。他热爱这份工作。
Andrea and Peter studied Russian at school. He thought they were very difficult.Correct -> Andrea and Peter studied Russian at school. They thought it was very difficult.
(正确)安德里亚和皮特在学校里学习了俄语。他们觉得俄语很难。
Missing Commas After Linking Language
连接语言后漏掉了逗号
When using an introductory phrase as linking language such as a conjunctive adverb or sequencing word, use a comma after the phrase to continue the sentence.
当我们使用介绍性短语，例如连接副词或表示顺序的词语，通常会在短语后面打上逗号来连接下文。
