破折号 Dash
破折号等于两个连字号的长度（在打字时连打两次即可），而用途也比连字号较多，但有很多人都有误用或滥用破折号，尤其是撰写学术论文或求职信时，应注意减少使用。
（1）用破折号来表示语气或思想的突变：
例子：
He staggered, picked himself up, then fell backward－stone drunk at his wedding reception.
（2）用破折号来分隔或强调一插入语，包括同位语 appositives、例子或定义：
同位语：
Two of the strongest animals in the jungle are vegetarians—the elephant and the gorilla.
Dick Gregory, The Shadow that Scares Me
例子：
The care-takers—those who are helpers, nurturers, teachers, mothers—are still systematically devalued.
Ellen Goodman, “Just Woman’s Work?”
定义：
Personal space—“elbow room”—is a vital commodity for the human animal, and one that cannot be ignored without risking serious trouble.
Desmond Morris, Manwatching
（3）用破折号来引入摘要 summary：
例子：She wants high-style clothes, an elegant apartment, a modern car—in short, she wants money.
（4）用破折号来加强作者的论点：
例子：These five passages have not been picked out because they are especially bad—I could have quoted far worse if I have chosen—but because they illustrate various of the mental vices from which we now suffer.
George Orwell, “Politics and the English Language”
注意：
如果在一对玻折号中的句语包含问号（?）或感叹号（!），则把问号或感叹号放在破折号之前。但其它标点符号如逗号（,），冒号（:），分号（;）或句号（.）不能跟着使用破折号。
例子：
A first date—do you remember?—stays in the memory forever.
（5）谈话的句子中，用破折号来表示犹豫或中断说话：
例子：“Naturally,” said Mr Lorry. “Yes— I —“ After a pause, he added, again settling the crisp flaxen wig at the ears, “It is very difficult to begin.”
Charles Dickens, A Tale of Two Cities
连字符 Hyphen
（1）连接两字或多个字成为一形容词来形容一名词，并放于一名词之前：
例子：
sixteen-year-old son
up-to-date information
注意：
I） 在名词之后，不可用连结字，如下列所示：
His son is sixteen years old.
The information was clearly not up to date.
II） 不可用连字号将有 –ly 结尾的副词adverb和一形容词作连结，如下所示：
carefully developed plot
usually fine wine
（2）用连字号来表示分数，以及介乎二十至一百之复合数字：
分数例子：
one-fourth complete
a two-thirds majority
数字例子：
twenty-one
fifty-two
（3）用连字号来连结 root words 与前缀 prefixes 或后缀 suffixes：
前缀 prefixes：pro-, anti-, self-, great-, co-, all-
后缀 suffixes：-elect
例子：
pro-abolitionist
anti-abolitionist
self-confessed
great-grandmother
co-worker
all-loving
governor-elect
congressman-elect
（4）使用连字号来连结两个或以上的名词，使之成为复合词 compound nouns：
例子：
double-decker
half-light
hair-stylist
father-in-law