英语破折号输入及用法

英语破折号输入及用法
在记事本或者别的字处理软件中打出这三个符号的方法：
hyphen（-）：非常简单，就是键盘上＋号前那个符号；
en dash（–）：如果使用笔记本电脑，首先打开Numlock键，如果使用桌面电脑，打开数字锁定键，按下ALT，然后依次按下数字键0150；
em dash（—）：按下ALT，然后依次按下数字键0151。

最早在英语文章中看到这个长长的横线“—”时还以为是把连字号Hyphen打印错了，后来多次遇到它，便做了一些研究。

这并非hyphen，而是破折号，英语写作中经常用到。

英语名称叫：em dash。

另一个长度为其一半的符号叫en dash, 最短的才是连字号hyphen。

以下是三者的对比：
hyphen -
en dash –
em dash —
我在GSC Guide to Authors上查到了关于En dash和em dash的详细用法。

（GSC - The Geological Survey of Canada)
原文链接：
http://www.nrcan.gc.ca/ess/pubs/guide/index_e.html
Note: There are two kinds of dashes: the en dash, which is longer than the hyphen, and the em dash (space-long dash-space), which is twice as long as an en dash:
I. En dash
The en dash is used in these cases:
1)To join inclusive numbers or series:
p. 9–15
W.E. Logan (1798–1875)
10–15°C
January–June
but -8 to -20°C
2)In compound expressions joining place names:
the Great Lakes–St. Lawrence Lowlands
the Laurentide–Greenland ice sheets
3)in joining a one-word noun to a two-word noun in a compound adjective
a granodiorite–quartz monzonite phase
2. Em dash
This is usually referred to as the dash, and is a useful,
but overworked, punctuation mark. The em dash is used in
these instances:
1)as the equivalent of, or as a substitute for, parentheses.
A pair of dashes sets off material in parenthesis more directly and decisively than a pair of commas:
The Gadfly Formation—the name is the subject of much controversy—is found at only one locality in the map area.
2)to mark an unexpected turn of thought, particularly one that causes an abrupt break in
sentence structure:
The Englishman must not express great joy or sorrow or even open his mouth too wide when he talks—his pipe might fall out if he did.
— E.M. Forster
3)to mark the insertion of material that explains, amplifies, complements, or corrects:
The outcrop consists of limestone, gneiss, and salt—an unlikely combination that had been juxtaposed by faulting.
4)to gather up the subject of a sentence when it is a very long one:
Rich stores of minerals, good agricultural land, forests stretching over millions of acres, coastal waters teeming with fish, and energetic and enterprising people—all these assure Canada a bright future.
The em dash is not used immediately after a colon, semicolon, or comma.
英语破折号用法
1、em dash连接的句子前后都不能有空格。

2、除非遇到天生大写的字母，em dash后接的单词不能大写，例：
Juan tried begging, bribing, and even demanding cooperation from his staff—all of whom were swamped with other work—before he gave up and wrote the report himself.
3、en dash和em dash的得名，en dash的长度等于一个typesetter's letter N，而em dash 的长度则与一个M字母的长度相当。

因此，前者称为en dash，后者称为em dash，都是英文写作中经常用到的破折号。

4、en dash也要求前后不加空格。

5、表示时间、日期、空间等范围时，一律用en dash，而不是hyphen。

hyphen只用于连接单词构成复合词。

例如：Sitting-room, left-handed
It takes 3–6 days to get there.
5、-、–、—（这三个符号依次为hyphen、en dash、em dash，长度由左向右递增。