英语语法：130 Serial Comma

Grammar Girl here.

Today's topic is the serial¹ comma.

Here's a listener:

Hi, Grammar Girl. This is Patti from Houston...

Patti and her friends are debating about the serial comma—the comma that comes before the final conjunction in a list.  Here's a sentence that uses a serial comma: According to the Internet Movie Database, the top-grossing movies of all time in the United States are currently Titanic², Star Wars, and Shrek 2.

Whether to use the serial comma is a style issue, which is why Patti and her friends ended up in a debate.

Although the British are less likely to use serial commas than Americans (1, 2), primarily it's newspapers that allow writers to omit that final comma (1, 3). Newspapers are always looking to save space, and one argument for leaving the comma out is that it's unnecessary in simple sentences. Consider this sentence: According to the website Box Office Mojo, when ticket sales are adjusted for inflation, the top-grossing movies of all time in the United States are currently Gone with the Wind, Star Wars and The Sound of Music.

I didn't use a serial comma in that sentence, and there wasn't any confusion. That's the main argument against using the comma in every case—leaving it out often doesn't change anything. (And I apologize to the international listeners for using U.S. ticket sales in the example. I couldn't find inflation-adjusted numbers for worldwide box office sales.)
 
The serial comma is also sometimes called the Oxford³ comma because it's used by Oxford University Press or the Harvard comma because it's used by Harvard University Press, but I find these names misleading because so many other publications also use the serial comma.

Although the serial comma isn't always necessary, I favor it because often it does add clarity, and I believe in having a simple, consistent style, instead of trying to decide whether you need something on a case-by-case basis. I also think using the serial comma makes even simple lists easier to read. Really, unless space is incredibly expensive, I can't imagine why anyone would decide the best method is sometimes leave it out and sometimes add it in*.

The one thing everyone does seem to agree about is that you have to use the comma when leaving it out would create confusion, as is often the case when the items in the list have internal conjunctions or are complex in some other way (1, 3, 4, 5, 6, 7, 8). Here's a sentence that could mean different things with and without the final comma because one of the list items has an internal conjunction: Rebecca was proud of her new muffin recipes: blueberry, peanut butter and chocolate chip and coconut⁴.

Without a serial comma, you wouldn't know whether the last recipe is a combination of peanut butter and chocolate chip or a combination of chocolate chip and coconut. You can make the meaning clear in two ways: place the final comma after peanut butter or after chocolate chip, or rewrite the sentence so that there is no ambiguity⁵. 

If you want to say that the combination is peanut butter and chocolate chip, you can write blueberry, peanut butter and chocolate chip, and coconut, or if you insist on leaving out the serial comma, you can rewrite the list as peanut butter and chocolate chip, coconut and blueberry. But I still think the rewrite is more risky⁶ than the sentence with the serial comma because a reader who's just skimming the sentence could be tempted⁷ to think that coconut and blueberry is a combination.

Another case where leaving the comma out can be confusing is when the later items in the list can describe an earlier item. An oft-cited example is the made-up book dedication⁸ To my parents, Ayn Rand and God. A reasonable reader would assume there are four entities⁹ being thanked: mom, dad, Ayn Rand, and God; but without the serial comma you could also conclude that the two parents are Ayn Rand and God. A serial comma clears up any confusion: To my parents, Ayn Rand, and God. 

Finally, there are similar sentences where even a serial comma doesn't make the meaning clear. Consider this sentence: I went to see Zack, an officer and a gentleman.

Without the serial comma—I went to see Zack, an officer and a gentleman—it could mean that Zack is both an officer and a gentleman, or that I went to see three people: Zack, an unnamed officer, and an unnamed gentleman.

With the serial comma—I went to see Zack, an officer, and a gentleman—it could still mean two different things. It could mean I went to see three people (Zack, an unnamed officer, and an unnamed gentleman), or it could mean I went to see two people (Zack, who is an officer, and an unnamed gentleman).

So, the bottom line is that whether or not to use the serial comma is a style issue. Most publications except newspapers favor using it all the time, as do I, and all publications call for a serial comma when leaving it out could cause confusion. And sometimes sorting out your meaning is just too much for one little comma and the best option is to rewrite your sentence.

That's all.

I have an exciting announcement this week! My audiobook is coming out soon on a physical CD that you can buy in bookstores. Of course it will still be available to download from iTunes and Audible.com, but I know some people would rather have something they can hold in their hand or wrap up and give as a gift. It'll be available in all the major bookstores on July 24th, and you can already pre-order it online. I'll put a link at my website. QuickAndDirtyTips.com, and while you're there, be sure to also check out the other great Quick and Dirty Tips podcasts such as Money Girl. This week she's talking about how to avoid problems when you marry someone who has poor credit.

Also, for those of you who've asked, I am working on a paperback¹⁰ book, but those things take a really long time, so it probably won't be available until next year about this time.

Thanks for listening.
 

1 serial   

n.连本影片，连本电视节目；adj.连续的

参考例句：

• A new serial is starting on television tonight.今晚电视开播一部新的电视连续剧。
• Can you account for the serial failures in our experiment?你能解释我们实验屡屡失败的原因吗？

2 titanic   

adj.巨人的，庞大的，强大的

参考例句：

• We have been making titanic effort to achieve our purpose.我们一直在作极大的努力，以达到我们的目的。
• The island was created by titanic powers and they are still at work today.台湾岛是由一个至今仍然在运作的巨大力量塑造出来的。

3 Oxford   

n.牛津（英国城市）

参考例句：

• At present he has become a Professor of Chemistry at Oxford.他现在已是牛津大学的化学教授了。
• This is where the road to Oxford joins the road to London.这是去牛津的路与去伦敦的路的汇合处。

4 coconut   

n.椰子

参考例句：

• The husk of this coconut is particularly strong.椰子的外壳很明显非常坚固。
• The falling coconut gave him a terrific bang on the head.那只掉下的椰子砰地击中他的脑袋。

5 ambiguity   

n.模棱两可；意义不明确

参考例句：

• The telegram was misunderstood because of its ambiguity.由于电文意义不明确而造成了误解。
• Her answer was above all ambiguity.她的回答毫不含糊。

6 risky   

adj.有风险的，冒险的

参考例句：

• It may be risky but we will chance it anyhow.这可能有危险，但我们无论如何要冒一冒险。
• He is well aware how risky this investment is.他心里对这项投资的风险十分清楚。

7 tempted   

v.怂恿（某人）干不正当的事；冒…的险（tempt的过去分词）

参考例句：

• I was sorely tempted to complain, but I didn't. 我极想发牢骚，但还是没开口。
• I was tempted by the dessert menu. 甜食菜单馋得我垂涎欲滴。

8 dedication   

n.奉献，献身，致力，题献，献辞

参考例句：

• We admire her courage,compassion and dedication.我们钦佩她的勇气、爱心和奉献精神。
• Her dedication to her work was admirable.她对工作的奉献精神可钦可佩。

9 entities   

实体对像； 实体，独立存在体，实际存在物( entity的名词复数 )

参考例句：

• Our newspaper and our printing business form separate corporate entities. 我们的报纸和印刷业形成相对独立的企业实体。
• The North American continent is made up of three great structural entities. 北美大陆是由三个构造单元组成的。

10 paperback   

n.平装本，简装本

参考例句：

• A paperback edition is now available at bookshops.平装本现在在书店可以买到。
• Many books that are out of print are reissued in paperback form.许多绝版的书籍又以平装本形式重新出现。