留学论文中关于逗号的正确使用方法

　　在前面的文章中我们给大家介绍了一些比较常见的标点符号使用错误，不知道大家有没有犯过这些比较基本的错误呢?希望大家有的话可以改正过来。这篇文章小编想来详细地给大家说一下留学论文中关于逗号的正确使用方法。逗号的主要作用为了避免歧义且让读者的阅读速度更快，它的主要用法如下：

　　用“逗号+连词”来连接两个单独的句子

　　这里的句子必须是地位平等的两个句子，这样的连词有如下7种：and,but,or,nor,so,for以及yet，逗号的作用是连接两个独立的句子，告诉读者下面会开启另一个句子，下面我们来练习一下：

　　The department sponsored a seminar on college survival skills and it also hosted a barbecue for new students.

　　修改后应该是这样的：…skills,and..逗号前后是两个独立的句子，不加逗号会引起歧义。

　　当然这里也有例外，如果两个单独的句子都很短且不加逗号不会产生歧义，那么就可以不加逗号，比如：

　　The plane took off and we were on our way.

　　下面是留学生常犯的问题：

　　A good money manager controls expenses,and invests surplus dollars to meet future needs.

　　这个句子的问题在于and前后不是单独的句子，所以不用加逗号。

　　副词性短语开头的句子其后加逗号与主句隔开

　　如果一个句子是以副词性的短语或者从句开头，就要在这部分之后加一个逗号，其作用是引出接下来的主句，让我们看看下面的句子逗号应该加在哪里?

　　Near a small stream at the bottom of the canyon the park rangers discovered an abandoned mine.没错，应该加在canyon后面。

　　当然这种情况也有例外：如果副词性的短语非常短且不加逗号不会导致歧义，就可以不加，如：

　　In no time we were at 2,800 feet.

　　用逗号连接一系列并列的词、词组或者从句

　　Bubbles of air,leaves,ferns,bits of wood and insects are often found trapped in amber.要在wood后面加逗号。

　　Langston Hughes’s poetry is concerned with racial pride,social justice and the diversity of the African American experience.要在justice后面加逗号。

　　并列的多个形容词之间可用逗号连接

　　Roberto is a warm,gentle,affectionate father.

　　因为这三个形容词是分开单独修饰父亲的，所以之间可用逗号隔开，当然最后的逗号可以用and代替。

　　如果连续的形容词不能够单独修饰后面的名词，那么之间不加任何东西，如：

　　Three large gray shapes moved slowly toward us.

　　非限定性成分可用逗号隔开

　　限定性成分是用来限制所修饰成分的意义，如果去掉被修饰成分的意思会发生改变，这种情况下不能加任何逗号，比如说：

　　The campers need clothes that are durable.

　　反之，如果非限定性成分和被修饰词之间的关系不是那么紧密，它的作用是增加信息，如果去掉之后不影响被修饰成分的意思，如：

　　The campers need sturdy shoes,which are expensive.

　　The scientists,who represented eight different universities,met to review applications for the prestigious O’Hara Award.

　　上面两句话的重点信息在主句上面，从句的内容去掉之后不影响被修饰的名词在主句中的角色。除了定语从句，形容词性词组以及同位语词组也遵循上面的规则：

　　The helicopter,with its million-candlepower spotlight illuminating the area,circled above.(with its million-candlepower spotlight illuminating the area为非限定性成分，去掉之后对helicopter影响不大)

　　过渡词后面需要加逗号表达停顿

　　这类词包括：however,therefore,moreover,for example,as a matter of fact,in other words等等。

　　Minh did not understand our language;moreover,he was unfamiliar with our customs.

　　(moreover前面必须是分号，后面加一个逗号)

　　插入性信息要用逗号隔开

　　Evolution,as far as we know,doesn’t work this way.

　　The bass weighed about twelve pounds,give or take a few ounces.

　　对比强烈的词组要用逗号隔开

　　Unlike Robert,Celia loved dance contests.

　　一些习惯性的用法

　　1).在直呼以及Yes和No后面需要逗号：

　　Forgive me,Angela,for forgetting your birthday.

　　Yes,the loan will probably be approved.

　　2).反问句

　　The film was faithful to the book,wasn’t it?

　　3).直接引语中

　　In his“Letter from Birmingham Jail,”Martin Luther King Jr.wrote,“We know through painful experience that freedom is never voluntarily given by the oppressor;it must be demanded by the oppressed”

　　4).日期On December 12,1890,orders were sent out for the arrest of Sitting Bull.

　　5).地址John Lennon was born in Liverpool,England,in 1940.

　　6).人名后面紧跟的头衔之间要用逗号隔开Sandra Belinsky,MD,has been appointed to the hospital board.(MD=Medicine Doctor)

　　7).数字中3,500(此处逗号读成thousand)1,000,000(此处逗号读成million)2,000,222,222(此处逗号读成billion)

　　特殊情况下需要加逗号避免歧义

　　To err is human;to forgive,divine.这边作者省略了is All of the catastrophes that we had feared might happen,happened.

　　以上就是为大家整理的关于留学论文中逗号的正确使用方法，接下来让我们来看一些比较常见逗号使用错误，希望引起大家的重视。

　　1.下面这两个是最常见的错误

　　Marie Curie discovered radium,and later applied her work on radioactivity to medicine.

　　Jake told us that his illness is serious,but that changes in his lifestyle can improve his chances for survival.

　　第一个句子中的and是用来并列两个谓语动词，第二个句子中的but是用来并列两个宾语从句，所以两个句子中的逗号必须都要去掉!

　　2.不要用逗号将动词和其主语或者宾语隔开，大家来看两个病句

　　Zoos large enough to give the animals freedom to roam,are becoming more popular.Maxine Hong Kingston writes,that many Chinese American families struggle“to figure out how the invisible world the emigrants built around our childhoods fits in solid America”

　　两个句子的逗号都是多余的。

　　3.在进行列举的时候，不要在第一个项目前或者最后一个项目后添加逗号

　　Other causes of asthmatic attacks are,stress,change in temperature,and cold air.Ironically,even novels that focus on horror,evil,and alienation,often have themes of spiritual renewal and redemption.

　　4.在限定性修饰语和被修饰成分之间，不要加逗号

　　Drivers,who think they own the road,make cycling a dangerous sport.

　　(两个逗号都是多余的，有逗号语意很难理解。)

　　5.一个以状语从句结束的句子中间不加逗号

　　Don’t visit Paris at the height of the tourist season,unless you have booked hotel reservations.(这边的逗号多余)

　　6.其他常见的使用错误

　　a.Occasionally TV talk shows are performed live,but,more often they are taped.(but后面的逗号多余)

　　b.Although,the air was balmy,the water was too cold for swimming.(although后面的逗号多余)