英语语法：181 How to Write Percents

Grammar Girl here.

Today's topic is part II of the series on numbers: percentages and decimal points.

Percent Versus¹ Percentage

First let's get our terminology² right. In some cases percent and percentage can be interchangeable (1), but the easiest way to choose the right word for the right situation is to use percent with a number and percentage without a number. For example,

[Percent with a number] Forty percent of the chocolate was missing.
[Percentage without a number] What percentage of the chocolate was missing?
Percent Versus Per Cent

Also, in American English, when you write out the word percent, it's one word. It's more common to see the two-word version--per cent--in British English, but sources tell me the one-word version is becoming more common in Britain too (2, 3, 4). The evolution of the word is kind of interesting. It started out as the Latin phrase per centum, which means "by the hundred (1)," and over the years got shortened to the two-word English version, and is now quite established as a single English word (2).

Singular or Plural³?

Now, earlier this afternoon Shaun Klein asked me on Twitter whether percentages are singular or plural, and as is so often the case, the answer is "It depends." If you're referring to a percentage of something, then that something determines whether you use a singular or plural verb. (In technical terms, that "something" is called the object of the preposition. The preposition is the word of.) Here's an example:
 
Forty percent of the chocolate is missing. (In that sentence the chocolate is singular so you use a singular verb.)
Forty percent of the chocolate chips are missing. (In that sentence the chocolate chips is plural so you use a plural verb.)

 

But what if there's no preposition or object of the preposition after the word percent? You've lost your clue! First, ask yourself if it's implied. If the implied phrase is singular use a singular verb, and if it's plural use a plural verb. Here's an example:
 
The chocolate chips were pillaged⁴. [new sentence] Forty percent were missing. (In the second sentence, the plural phrase--the chocolate chips--is the implied object of the preposition, so you use the plural verb--were.)
In the next example, the implied object is singular so you use a singular verb: The chocolate was pillaged. Forty percent was missing.

Finally, if you have no way to figure out whether the word percent is referring to something singular or plural, you can use whatever verb you like--singular or plural--it's that easy (5).
 
Web Bonus

It's a little more complicated with the word percentage. The same rules I just told you apply when you are talking about a percentage of something: singular something, singular verb; plural something, plural verb. But when you are talking about the percentage of something, then it is always singular (6).
 
A percentage of the chocolate chips were missing.
The percentage of chocolate chips missing was shocking.
 
Also, for percentage, the order of the sentence matters. If the percentage phrase comes later in the sentence, you need a singular verb (2).
 
A percentage of the chocolate chips were missing.
There is a large percentage of chocolate chips missing.

Words or Symbols

So now that you know how to use percents, let's talk about how to write percents in a sentence. Unlike what I told you last week for the general rules about writing numbers, for percentages it's better to use the numeral and not the word, even if it's a number less than 10. If you're writing about the 5% of chocolate chips that were damaged, use the numeral 5 and not the word five. The only time you would write out the word instead of using the number is if the number was at the beginning of the sentence. Then the rule about not starting a sentence with a numeral takes precedence and you write out the word (7, 8,9). [Note, some style guides disagree and say you can use the word or the numeral when writing out percents (10).]

Next you have to decide whether to use percent the word or percent the symbol. This is kind of like the general rule about writing numbers. If you're writing a technical or scientific document, then most sources recommend that you use the symbol. If you are writing something where numbers are used less frequently, then it is more common to write the word percent. Ultimately, it's a style issue, so make a decision and stick with it. Just remember to use the numeral and not the word for the number.

Decimals

If you're talking about a percent that is less than one, make sure you put a zero before the decimal point. Write something like 0.2%, not just .2%. This is true for writing any numeral that is less than one whether it's a percent or not (10, 11). That little decimal point is too easy to miss without the zero in front of it.

Lies, D*** Lies, and Percentages

Finally, there are a couple of things you should know about calculating and interpreting percentages.

First, something can't decrease by more than 100%. Once 100% of something is gone, there isn't anything left. Never write that a price or anything else decreased by 150%. It's impossible*.

Second, when you are reading about medical, political, or financial news it is important to understand that big percentages can mean small overall increases or decreases. For example, an article that reports a 50% increase in the rate of a rare disease may be telling you that instead of 1 in 100,000 people getting floogety flork disease every year, now 1.5 people in 100,000 get the disease every year. A 50% increase sounds a lot scarier than the increase in raw numbers. Percentages aren't always misleading, but it's something to watch out for.

I know I said I'd cover writing numbers over a million and the use of hyphens, but I'm out of time. I'll put the answers in the e-mail newsletter early next week, so make sure you're subscribed⁶. It's the blue button in the left-hand sidebar at quickanddirtytips.com. [Or subscribe⁵ to the newsletter here.]

Book Winners

Now it's free book time! First I have three signed copies of Scott Sigler's new book, Infected, for three lucky winners who are subscribed to my e-mail newsletter: Chris, Christy, and Monica all get a copy of Infected, which hit number one on Amazon's horror list this week. Thanks to Scott for providing the books. His info is at scottsigler.com.

Questions and comments for me go to。。。or the voicemail line at 206-338-GIRL. There's a Web bonus this week about the word percentage, and you can read it in the full transcript⁷ of this podcast at。。。where you can find the other great shows including Money Girl, The Mighty⁸ Mommy, and The Get-It-Done Guy.

That's all. Thanks for listening.

 

1 versus   

prep.以…为对手，对；与…相比之下

参考例句：

• The big match tonight is England versus Spain.今晚的大赛是英格兰对西班牙。
• The most exciting game was Harvard versus Yale.最富紧张刺激的球赛是哈佛队对耶鲁队。

2 terminology   

n.术语；专有名词

参考例句：

• He particularly criticized the terminology in the document.他特别批评了文件中使用的术语。
• The article uses rather specialized musical terminology.这篇文章用了相当专业的音乐术语。

3 plural   

n.复数；复数形式；adj.复数的

参考例句：

• Most plural nouns in English end in's '.英语的复数名词多以s结尾。
• Here you should use plural pronoun.这里你应该用复数代词。

4 pillaged   

v.抢劫，掠夺( pillage的过去式和过去分词 )

参考例句：

• They are to be pillaged and terrorised in Hitler's fury and revenge. 在希特勒的狂怒和报复下，他们还遭到掠夺和恐怖统治。 来自辞典例句
• They villages were pillaged and their crops destroyed. 他们的村子被抢，他们的庄稼被毁。 来自辞典例句

5 subscribe   

vi.(to)订阅，订购；同意；vt.捐助，赞助

参考例句：

• I heartily subscribe to that sentiment.我十分赞同那个观点。
• The magazine is trying to get more readers to subscribe.该杂志正大力发展新订户。

6 subscribed   

v.捐助( subscribe的过去式和过去分词 )；签署，题词；订阅；同意

参考例句：

• It is not a theory that is commonly subscribed to. 一般人并不赞成这个理论。 来自《简明英汉词典》
• I subscribed my name to the document. 我在文件上签了字。 来自《简明英汉词典》

7 transcript   

n.抄本，誊本，副本，肄业证书

参考例句：

• A transcript of the tapes was presented as evidence in court.一份录音带的文字本作为证据被呈交法庭。
• They wouldn't let me have a transcript of the interview.他们拒绝给我一份采访的文字整理稿。

8 mighty   

adj.强有力的；巨大的

参考例句：

• A mighty force was about to break loose.一股巨大的力量即将迸发而出。
• The mighty iceberg came into view.巨大的冰山出现在眼前。