During the recent gathering of the American Copy Editors Society, a lot of “hyphen” jokes made the rounds. One was “Why we need hyphens: Because thirty-odd editors is not the same as thirty odd editors.”
In the first example, “thirty” and “odd” create a sort of number, and need to be joined together, the way “thirty-one” would be. In the second example, “thirty” and “odd” both modify “editors,” but they are independent of each other, so are not hyphenated, the way “a big blue box” is not hyphenated. And, of course, the first example counts the editors, while the second counts and judges them.
Need another example of why we need hyphens? This, from the ACES conference Twitter feed:
“Because the second-best margarita in Phoenix is not the same as the second best margarita in Phoenix.” In the first case, it is not the best margarita in town, but No. 2; “second” modifies not “margarita” but “best,” and so needs to be joined to it. In the second case, it is the best margarita in town, and you’re having another, thank you. “Second” modifies “margarita,” not “best,” so should not be joined.
Frequently, your ear will help you decide whether to hyphenate two modifying words.
• Do you pause, ever so slightly, between them? Then you may not want a hyphen. “Thirty odd editors” has a slightly different rhythm than “thirty-odd editors.”
• Is there a possibility of someone misunderstanding which word is being modified? Is “a small business owner” a short shopkeeper or someone who owns a small business? If the latter, you probably want to make it “small-business owner.”
By the way, that little horizontal line is not a dash.
Sometimes, whether to use a hyphen is a matter of style or the dictionary you use. Are prefixes hyphenated? Sometimes yes, sometimes no, which is why “antiwar” and “anti-war” appear in nearly equal numbers. “Ex-” always takes a hyphen, while your “ex-wife’s” “great-grandfather” or her “half sister” may or may not be hyphenated.
But hyphens can be overused, too. Do you really need one in “day care center” or “health care debate”? Even if you think grammar demands it, let common sense guide your hand. Especially because “daycare” and “healthcare” are well on their way to becoming acceptable spellings.
Many dictionaries and style guides encourage judicious use of hyphens. The Associated Press Stylebook says: “It is optional in most cases, a matter of taste, judgment and style sense. But the fewer hyphens the better; use them only when not using them causes confusion.” The Chicago Manual of Style says: “A hyphen can make for easier reading by showing structure and, often, pronunciation. Words that might otherwise be misread, such as re-creation or co-op, should be hyphenated.”
Sometimes, though, you might want to use a hyphen even if the dictionary doesn’t. Are you a “onetime” thief (you used to be a thief) or a “one-time” thief (you stole only once)? In a state with a “three strikes” law, that little hyphen could affect more than one type of sentence.