Okay, enough CMOS changes. (You can follow The Chicago Manual of Style on Facebook if you want more tips.) Let’s get back to editing tips. This one’s on EM DASHES.
There are two types of dashes used in book manuscripts:
em dash: —
en dash: –
According to The Chicago Manual of Style (Rule #6.90 & 6.91 in the 15th edition) and The Christian Writer’s Manual of Style (pp. 165–166), an em dash should be used to denote a sudden break in thought that causes an abrupt change in sentence structure. For example:
“Will he—can he—obtain the necessary signatures?”
The em dash is also used to indicate that one person’s speech has been interrupted by another.
“Well,” he began, “I thought I might—”
“Might what?” Jayna interrupted.
The Chicago manual also states (#6.88 in 15th) that a defining or enumerating complementary element in a sentence may be set off by dashes.
“Suzette could forgive every insult but the last—the snub by her coauthor.”
“Three novelists—Francine Rivers, Angela Elwell Hunt, and Karen Kingsbury—have most influenced my own writing.”
CMS-15 #6.87 and CWMS (p. 167) recommend that no more than a single dash (or pair of dashes) be used in a sentence. Dashes should be used sparingly throughout a manuscript.
Most word processors can convert hyphens to dashes. In MS Word, go to Tools, AutoCorrect, AutoFormat. Put a check in “Symbol characters (–) with symbols (—).”
With that option selected, hold down the Ctrl and Alt keys, then hit the hyphen on your numeric keypad to make an em dash.
Or, you can type a word (no space after), then type a double-hyphen, then type the next letter or word followed by a space.
If you prefer, a double hyphen (–) can be typed to represent an em dash, with no spaces before, after, or in between.
Note: For article manuscripts (per the Associated Press Stylebook), insert a space before and after an em dash (or double hyphen).