英语语法：24 Units Of Measure

Grammar Girl here.

Today's topic is units of measure—those words and symbols that come after numbers.

This first point might seem self-evident: you put a space between the number and the unit of measure. Even though it seems obvious, I'm telling you because I've seen people do it wrong, and there are also exceptions to the rule.

For example, if you want to say you threw a ball 100 feet, there is a space between the number 100 and the word feet. Obvious, right? But what if you abbreviate¹ feet to ft*? It's the same rule: there's a space between 100 and ft, and if you just think of the abbreviation as the word, it should be easy to remember, but I've seen them squished together without a space many times.

Sometimes I think people get confused because there are at least two exceptions to that rule—percent and degrees—but it helps to remember that these exceptions occur when you are using symbols instead of abbreviations. For example, if you are writing out the words 100 degrees, there is a space between the number 100 and the word degrees, but if you are using the degree symbol, that little superscript circle, you butt² it right up against the number without any spaces in between (100°—no space). The same holds true if you want to use the percent sign. Even though you use a space when you are writing out the word percent, if you use the percent sign, it goes right after the number without any spaces (100%—no space).

For the next point, let's go back to talking about feet. The singular is obviously foot, and the plural³ is usually feet, except when you are using it as a compound modifier. You would say that Squiggly climbed a tree that was 10 feet tall†; feet is plural there. But you don't say Squiggly ran up a 10-feet tree—you say Squiggly ran up a 10-foot tree. Foot is plural when it's part of a compound modifier. That's also true for other units of measure like inches and pounds. Squiggly was running from a 100-pound monster, and he nearly lost his 10-inch tentacles⁴.

Similarly, the abbreviations for units of measure are the same whether the units are singular or plural. the abbreviation is ft. whether it is foot or feet.  Occasionally you will see an s after the abbreviation for pounds, lbs., but it isn't necessary.

Style guides are divided about whether you need to put a period after the abbreviations for English units of measure like feet, inches, and pounds‡. So it's up to you to pick a style and use it consistently. In general, it's more common to use periods in the U.S. than in Britain (1). With the metric system, or more formally the International System of Units, you never use a period after the abbreviations (2).

And here's a bonus: Have you ever wondered why pounds is abbreviated⁵ as lb instead of pd or something that relates to how it is actually spelled? As is often the case, it has to do with Latin. The abbreviation lb stands for the Latin phrase libre pondo, which means "pound of weight." There are some really extensive explanations on the web, so I put a few links in the blog.

 

Math Forum⁶ Explanation
World Wide Words Explanation
 

* Most style guides recommend writing out units of measure (e.g., feet instead of ft.) unless you are writing a technical or scientific document. Abbreviations are acceptable in tables.

† The Oxford⁷ Dictionary of English Usage states that “foot” can also be used in this sentence, as in “Squiggly climbed a tree that was 10 foot tall.” It notes that this use is correct, but less common.

‡ For example, The Chicago Manual of Style (14th edition) states that abbreviations are usually written without periods (p.477), but goes on later to give examples with periods. The Modern Language Association Handbook gives examples with periods, but notes that the trend in abbreviations is away from using periods.

That's all.

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1 abbreviate   

v.缩写，使...简略，缩短

参考例句：

• She had lost the power to abbreviate the remaining steps of the way.她丧失了缩短这最后几步路的能力。
• It is seldom acceptable to abbreviate words in formal writing.在正式的书面语中使用缩写语通常是不能接受的。

2 butt   

n.笑柄；烟蒂；枪托；臀部；v.用头撞或顶

参考例句：

• The water butt catches the overflow from this pipe.大水桶盛接管子里流出的东西。
• He was the butt of their jokes.他是他们的笑柄。

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 tentacles   

n.触手( tentacle的名词复数 )；触角；触须；触毛

参考例句：

• Tentacles of fear closed around her body. 恐惧的阴影笼罩着她。
• Many molluscs have tentacles. 很多软体动物有触角。 来自《简明英汉词典》

5 abbreviated   

adj. 简短的，省略的 动词abbreviate的过去式和过去分词

参考例句：

• He abbreviated so much that it was hard to understand his article. 他的文章缩写词使用太多，令人费解。
• The United States of America is commonly abbreviated to U.S.A.. 美利坚合众国常被缩略为U.S.A.。

6 forum   

n.论坛，讨论会

参考例句：

• They're holding a forum on new ways of teaching history.他们正在举行历史教学讨论会。
• The organisation would provide a forum where problems could be discussed.这个组织将提供一个可以讨论问题的平台。

7 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。

8 eligible   

adj.有条件被选中的；(尤指婚姻等)合适(意)的

参考例句：

• He is an eligible young man.他是一个合格的年轻人。
• Helen married an eligible bachelor.海伦嫁给了一个中意的单身汉。

9 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》

10 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。

11 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。