One of the dead giveaways of a non-professional book is misusing the poor hyphen instead of a dash.
Let’s clear something up right away: a hyphen is not the same thing as a short dash, which is distinct from a long dash. They are three different punctuation marks, each with their own uses and rules. They are not interchangeable.
What they’re for
For example, a hyphen can combine two words into one, as in “long-term effects” or “father-in-law.” A hyphen helps avoid confusion in phrases like “high-school students,” which can be very different from “high school students.”
Hyphens also join numbers when they’re written out, such as “forty-two.”
Finally, hyphens indicate that a word is broken at the end of a line of text, when a word is too long to fit on a single line of text. Remember that you break the word between two syllables, with a few exceptions like “ther-apist.”
Dashes: the short and the long
There are two types of dashes. The short dash, also known as the “en dash” is twice as long as a hyphen. It’s also called the en dash because it’s the same width as a letter N. It’s used to indicate a range, most often in numbers, such as “pages 25–35.” It can also be used to indicate a range in space, like “a Toronto–Montreal flight.” However, most style guides recommend that use more for tables and illustrations, but in body text, to write “Toronto to Montreal.”
En dashes can also join words that already have hyphens (which is relatively rare), as in “private-sector–public-sector cooperation,” or when joining two things where one is two separate words, such as “pre–Second World War era.”
The long dash is also called the em dash because it’s the same width as a capital letter M, itself usually the widest letter in the alphabet. An em is twice as wide as an en.
The em-dash is used to link phrases and sentences, or to indicate an abrupt change in thought or logic. Here’s an example from my upcoming new book, Wildfire:
She had seen a question in her green eyes—was she really going to apply for a job in a restaurant?
It can take the place of parentheses or a colon, as in these examples from Wikipedia:
The food—which was delicious—reminded me of home.
Three alkali metals are the usual substituents—sodium, potassium, and lithium.
How to do it
Part of the problem with en and em dashes is that they don’t appear on the standard typewriter keyboard. Those of us who learned to type on typewriters—back in the day—learned to use multiple hyphens when we wanted a long dash. There was simply no other way to do it.
That limitation has survived, even though with our word processors, there’s no reason for it. Seriously, there are keys on the main part of my computer keyboard I almost never use, while getting the dash which I use frequently requires pressing three keys at once. Why a pipe symbol? Why curly brackets?
The way to geta an en dash in Microsoft Word on a Windows computer is to hold down the Ctrl key and press the minus sign at the top right of the number keypad.
On a Macintosh, again using Word, it’s done by holding down the Option key and pressing the hyphen or minus sign.
You can also type the alternative character code: hold down Alt (Windows) or Option (Mac) and type 0150.
Insert an em dash by adding the Ctrl key on Windows: Ctrl-Alt-Minus. On a Mac, it’s Shift-Option-Minus. The alt key code is Alt 0151. On a Macintosh, hold down the Option key.
On-screen typing
Tablets have made this easier. All you have to do is hold your finger down on the hyphen “key.” In a couple of seconds, you’ll get a menu of choices. Select the appropriate punctuation mark.
Spaced out or not
Some people like to put a single space on both sides of em dashes — like this — while others like them tight—like that. Whichever you choose, be consistent.
This may seem like a trivial matter, but hyphens and dashes stand out on a page or a screen, and they clearly signal someone who doesn’t appreciate the difference—and that a professional editor had not seen that page.
It’s almost as blatant as misusing quotation marks, but I’ll write more about that in another post.