英文写作标点符号怎么用?
许多人不清楚在英文写作时标点符号该如何使用，但在写作学术论文时，遵循标点符号的使用准则是非常重要的。举个简单的例子，如果用逗号分隔两个独立不相关的句子会让读者感到困惑，但若适当的使用分号分隔则可使文章更加通顺易懂。因此，当在英文论文或文章中使用标点符号，如逗号comma (,), 冒号colon (:), 分号semicolon (;), 或破折号dash (—)时，请注意以下使用准则：
英文写作中如何使用逗号(Comma)
在大部分的写作中，逗号是最常被使用的标点符号。但因为逗号的使用场景和使用要求最多，因此许多人会对如何正确使用感到困惑，以下是逗号的几点重要功能，以及适当的使用时机。
罗列事物或短语时:
- I bought bread, cheese, and pickles at the grocery store.
需要分隔两个独立的较长从句，并使用连接词连接时：
- Astronomers have known about the positions of stars for centuries, but they didn’t understand that the earth revolves around the sun.
在介绍性短句的后面:
- In preparation for the next convention, the representatives studied up on the most important issues.
当需要区分附加说明部分的句子(parenthetical phrase)，或要分隔插入语(interrupter)时:
- All doctors, if they care about their patients, are concerned with good office hygiene.
逗号的常见错误使用案例
Comma splice. 不要在未使用连接词的情况下，使用逗号分隔两个独立的从句
- 错误范例: Thousands of protesters showed up on the streets, they were shouting and carrying large posters.
- 正确范例: Thousands of protesters showed up on the streets; they were shouting and carrying large posters.
Combining lengthy phrases. 在复合句中使用逗号或用逗号来分隔短句会造成读者的困惑，这种情况应使用分号。
- 错误范例: 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.
- 正确范例: 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.
英文写作中如何使用冒号(Colon)
冒号来条列下文，并告诉读者 “Here’s what I mean.”。通常在英文写作中，冒号不常被使用，除非您有许多内容需要列举，冒号的使用准则较为严谨，但也相对容易被记住。
介绍一个或多个项目：
- Humans use five major senses: sight, hearing, smell, taste, and touch.
分隔两个独立从句，第二个从句用来叙述、说明、改写或延伸第一个从句：
- Martha realized that her worst fear was coming true: her son was being sent to war.
(*冒号后用独立的从句解释Martha’s fear)
商业书信或正式信件开头问候语：
- To the Central Valley Committee Chairman:
其他冒号使用准则
冒号后的第一个字母不要大写，除非是专有名词， is part of a quote, or is the first in a series of sentences:
- 错误范例: I have three desires: To eat, sleep, and work.
- 正确范例 : I have three desires: to eat, sleep, and work.
当引号内包含多个句子，许多作者会倾向使用冒号而非逗号来引出内容：
- 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.”
接在冒号之后的内容不一定要是完整的句子，可以是单词或短语：
- There is one mantra that can sum up our position towards climate change: urgent action.
常见冒号错误
分隔平等并且无相关的两个从句：
- 错误范例: Sarah and her friends loved spending time on the mountain : nature always held a special meaning for them.
- 正确范例: Sarah and her friends loved spending time on the mountain ; nature always held a special meaning for them.
(*若两个从句完全无相关，则应使用句号；若第二个从句和第一个从句有某种程度相关，并且并非用来陈述、说明或改写第一个子句，则使用分号分隔)
过度使用冒号:
冒号属于强调性质的标点符号，要避免过多使用。请将冒号想像为暂停标志，用来引起读者注意“Hey! Pay attention to this. This is important.” 如果路上有过多的暂停标志，则无法顺利并快速的前进，同样的道理，若文章中包含过多的冒号，读者也无法顺利阅读。
冒号主要用来吸引读者注意力并清楚的指出重要信息，因此，许多作者会使用冒号来导出他们的重要主张或是用来支撑证明。
英文写作中如何使用分号(Semicolon)
分号使用在分隔两个独立的概念(两个独立的从句)，但这两个句子是有相关性的。当陈列复杂的概念或短语，并且句中包含逗号时，适合使用分号来分隔。分号拥有逗号的功能，但包含更多意思，亦有有冒号的功能，但更有弹性。
在句中加入两个或多个概念，而这些概念互为平等时：
- The universe has always called to human beings; there could be no more final frontier than space.
加入两个用连接副词或转折片语连接的独立从句：
- 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.
陈列许多或一系列不同的项目，项目中包含逗号时，或者项目相对长且性质较复杂：
- Our family members came all the way from Denver, Colorado; Rochester, Minnesota; and even Paris, France.
使用对等连接词连接两个独立从句(若两个从句已使用逗号分隔)，或者当两个从句较长时：
- 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.
应使用分号而非逗号的情况
- 错误范例: The specimens were treated properly, however, they were not stored properly.
- 正确范例: The specimens were treated properly; however, they were not stored properly.
*副词“however”表示的是连接两个独立的从句； 不要用逗号去连接两个不包含并列连词(and, but, or, nor 等等)的独立从句。
- 错误范例: 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!
- 正确范例: 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!
*若只使用逗号，则无法清楚的表明陈列的项目是什么。因此，要善用冒号用来分开包含逗号的项目。
英文写作中如何使用破折号(Dashes)
破折号应可被视为用途最多样的标点符号，但是，如同分号，破折号在很多文章中都并未被适当活用。在许多情况下，破折号可以被当作逗号、括号或是冒号使用，但却可以带来细微的差异。
使用破折号替代逗号
当写到插入语时，前后各使用一个破折号可以代替逗号，破折号更有强调之意，让读者能更加集中在破折号中提到的讯息。
使用逗号导入插入语:
- 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 .
使用破折号导入插入语:
- 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”baby was premature”的重点，表现出此内容在句中的重要性)
使用破折号替代括号
前后各使用一个破折号可代替括号，因为破折号较为非正式，因此在学术英文中较少出现。但是，使用破折号可较明显的将句子中断，因此也更能强调内容。
当使用破折号代替括号时，原来接在括号后的标点符号应删除：
- 使用括号：After taking all of his final exams (including seven essays and three multiple choice tests), David just wanted to sleep.
- 使用破折号：After taking all of his final exams—including seven essays and three multiple choice tests—David just wanted to sleep.
*破折号较为显而易见，因此较能有效地中断句子并吸引读者注意。
若为在句子的最后选择使用破折号代替括号，则只需要使用一个破折号(而非前后各一)
- 使用括弧: That coffee shop offers a selection of exotic gourmet coffee (or at least that is how they describe it).
- 使用破折号: That coffee shop offers a selection of exotic gourmet coffee—or at least that is how they describe it.
*The dash seems to work especially well when placed at the end of a sentence—it extends the sentence like an addendum .
使用破折号替代冒号
当在强调句子的结论时，使用破折号代替冒号可以带出不一样的意义：破折号可导出附加的内容，且使用方式更为弹性；破折号和冒号相比较为非正式。
- 冒号: The executives finally decided what they would do with the company: sell it at a loss.
- 单一破折号: 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!
- 单一破折号: Let’s go where we went last year—Disneyland!
*这里使用破折号可以传达出一种期待感（或不可避性）,也会让文章带有社论色彩。
在使用符号时，要考虑到上下文内容及读者
在撰写文章并选用标点符号时，应考虑书写的内容为何、读者为谁。举例而言，研究者若想在期刊上发表论文，应该先了解该期刊大部分的作者如何使用标点符号。在撰写新闻、杂志等英文文章内容时，也是采取同样的原则。
