学术论文中标点符号的使用(可见标点符号确实很重要)，特别是对语法结构迥异的中国学生而言，英文标点符号的使用常常与句子的结构、意义以及语法的使用密切相关。尽管我们在第一部分的最后一部分中也提到了对标点符号的使用，但这一部分我们将对逗号(、)(🙂分号(😉和破折号(-)再作一次深入的说明，并附上具体的实例说明。需要代写请联系客服。

Which Punctuation Mark Should I Use?

使用标点的规则非常重要，特别是在学术著作中。用逗号来区分两个不同的分句，会使读者迷惑，使你的文章读起来疲惫不堪。相反，一个合适的分号可以给任何一篇文章添加一些微妙的东西。使用逗号(,)、冒号(🙂、分号(😉或破折号(-)时，要记住下列规则。

▶ 1 When to Use a Comma

在大多数写作中，最常使用逗号(而且最常被滥用)。这是因为它有许多用途和规律，所以很难归纳出来。首先，我们来看一下逗号的一些重要功能，然后讨论什么时候用逗号代替其它类似的标点。

列出项目或短语:

I bought bread, cheese, and pickles at the grocery store.

当用连词连接长独立子句时，将其分开:

Astronomers have known about the positions of stars for centuries, but they didn’t understand that the earth revolves around the sun.

在一个介绍性短语之后:

In preparation for the next convention, the representatives studied up on the most important issues.

把插入语或中断语分开:

All doctors, if they care about their patients, are concerned with good office hygiene.

Common Comma Mistakes

逗号粘连。不要用逗号分隔两个没有连词的独立分句。

Incorrect: Thousands of protesters showed up on the streets, they were shouting and carrying large posters.

Correct: Thousands of protesters showed up on the streets; they were shouting and carrying large posters.

结合冗长的短语。在复合句中使用逗号或在从句中使用其他逗号会造成混淆。使用分号。

Incorrect: Some useful subjects are English, which is an international language, math, which is used in all domains of sciences and social sciences, and philosophy, which underpins many other areas of study.

Correct: Some useful subjects are English, which is an international language; math, which is used in all sciences and social sciences; and philosophy, which underpins many other areas of study.

▶ 2 When to Use a Colon

用冒号来列出清单，并告诉读者：“这就是我的意思。”除非有大量的清单，否则冒号在大多数写作中都不应该经常使用。“冒号”的规则非常严格，但是很容易记住。

介绍一项或一系列的项目:

Humans use five major senses: sight, hearing, smell, taste, and touch.

当第二个从句/句子阐释、解释、释义或扩展前一个句子时，将独立的从句分开:

Martha realized that her worst fear was coming true: her son was being sent to war.

在商务信函或更正式的信函中跟随称呼:

To the Central Valley Committee Chairman:

More Tips For Using Colons

不要把冒号后面的第一个单词大写，除非它是一个专有名词，是引用的一部分，或者是一系列句子中的第一个:

Incorrect: I have three desires: To eat, sleep, and work.

Correct: I have three desires: to eat, sleep, and work.

当引文包含多个句子时，许多作者更喜欢用冒号而不是逗号来介绍:

In Chapter 3, the author explains his theory: “Dogs have dreams, but they don’t dream as humans do. Their dreams reflect a primal desire for pleasure, whereas humans are preoccupied with the ego and self-image. This is equally true in wakefulness and sleep.”

一个完整的句子在冒号后面是没有必要的，一个单词或短语就可以了。

There is one mantra that can sum up our position towards climate change: urgent action.

Common Colon Mistakes

分隔两个具有相同等级或不相关信息的子句:

Incorrect: Sarah and her friends loved spending time on the mountain: nature always held a special meaning for them.

Correct: Sarah and her friends loved spending time on the mountain; nature always held a special meaning for them.

(*如分句完全无关，可用句号。如果第二个分句中的信息有些相关，但没有说明、解释或解释第一个分句，请使用分号。)

过度使用冒号

冒号是一个强有力的标点符号，应该尽可能少使用它。想想看，就像一个停车标志，吸引读者的注意，然后说：“嗨！这个问题值得关注。如果街道上有太多的停车标志，你就不能把车开得平顺或快速。因此冒号对读者也有同样的影响。

由于冒号很引人注目，他们能清楚地指出哪些信息很重要。因此，许多作家用冒号来说明他们的主要论点或支持他们的证据。

▶ 3 When to Use a Semicolon

分号是用来分隔两个密切相关的概念(两个独立的句子)。他们也可以用逗号来列出复杂的思想或短语。实质上，分号和逗号一样，具有更多的含义，或者像冒号一样，具有更大的灵活性。

在一个句子中加入两个或两个以上的观点(部分)，当他们的观点被给予同等的地位或地位:

The universe has always called to human beings; there could be no more final frontier than space.

连接两个由连接副词或过渡短语连接的独立子句:

Sam thought David was inviting him to the picnic to enjoy a nice day out; as it turned out, David was planning a surprise birthday party.

如果项目中有逗号，或者项目相对较长且复杂，则在列表或系列中显示项目:

My main research objective is to isolate the cause of the disease, as well as to contribute to the existing literature; for this will bring an end to starvation across the continent, create new study designs related to epidemiology, and change the very paradigm of my research field.

Using a Semicolon Instead of a Comma

Incorrect: The specimens were treated properly, however, they were not stored properly.

Correct: The specimens were treated properly; however, they were not stored properly.

（*连接副词“however”表示两个独立分句之间的联系;如果没有并列连词(and, but, or, nor等)，不要用逗号连接两个独立的子句。）

Incorrect: The sun is wonderful: it produces light, which plants need to survive, it gives us warmth, which is useful for most life, and it makes a sad day happier, which is obviously a positive trait!

Correct: The sun is wonderful: it produces light, which plants need to survive; it gives us warmth, which is useful for most life; and it makes a sad day happier, which is obviously a positive trait!

（*仅使用逗号，尚不清楚具体列出了哪些项目。分号帮助分隔列出的项目，每个项目都包含逗号。）

▶ 4 When to Use a Dash (or Dashes)

划线(或更确切地说，“em划线”)可能是最常用的标点。但是，就像分号一样，它并没有被用于大多数写作。其作用方式与逗号、括号或冒号相似，但在每一种情况下有细微的不同。

用破折号代替逗号

Em dash(长破折号)可以成对使用，在编写插入语或中断短语时替换逗号。破折号有一种更强调的感觉，让读者关注设置在特殊标记内的信息。

带逗号的插入语:

And so, when the baby was born in June, nearly two months premature, the parents were happy but quite nervous, and they still had to buy all of the baby supplies.

带破折号的插入语:

And so, when the baby was born in June—nearly two months premature—the parents were happy but quite nervous, and they still had to buy all of the baby supplies.

(*破折号强调婴儿早产的事实，表明这是这个句子中的一个重要细节。)

用破折号代替括号：

把两个破折号放在和括号相同的地方。由于破折号不太正式，因此在学术论文中破折号比括号要少。但是，它们的确造成了更明显的干扰，因而更加突出。它们也可以用作某种“meta”括号，因为它们之间的内容已经包含括号。

当破折号代替圆括号时，省略包围的标点符号:

圆括号: After taking all of his final exams (including seven essays and three multiple choice tests), David just wanted to sleep.

破折号: After taking all of his final exams—including seven essays and three multiple choice tests—David just wanted to sleep.

(*我们能够直观地感受到破折号在句子中存在感更加强烈，因此会打断句子的思路，让人更注意句子的内容。)

当在句末使用破折号而不是括号时，只使用一个破折号：

圆括号: That coffee shop offers a selection of exotic gourmet coffee (or at least that is how they describe it).

单破折号: That coffee shop offers a selection of exotic gourmet coffee—or at least that is how they describe it.

用长破折号代替冒号

当你想强调你的句子的结论而不给它冒号所带来的所有内涵时，使用破折号而不是冒号。破折号可以添加“额外的”信息，而且这种方式更加灵活。它也没有冒号那么正式。

冒号: The executives finally decided what they would do with the company: sell it at a loss.

单破折号: The executives finally decided what they would do with the company—sell it at a loss.

冒号: Let’s go where we went last year: Disneyland!

单破折号: Let’s go where we went last year—Disneyland!

（*以这种方式使用破折号传达了一种预期感(或必然性) ）

选择标点符号时要考虑上下文和读者

最后一个Tips: 与任何关于写作的技术决定一样，在选择使用哪种标点符号时，最好考虑一下你的读者和作品的背景。举例来说，想要在某一期刊发表文章的研究者应该阅读他们目标期刊上的文章，并查看该期刊上的大多数作者使用了什么标点符号，这一规则适用于任何你想写的报纸、杂志或期刊。