Q. Do you recommend using en dashes and em dashes in tweets? Or hyphens?
A. There are no obvious reasons not to use en dashes and em dashes in tweets aside from the extra effort they require to enter properly. To get either of them from a virtual keyboard, try holding down the hyphen to see more options (including en and em dashes); on physical keyboards, you’ll need a keyboard shortcut (e.g., Alt+0150 and Alt+0151 using the numeric keypad in Windows or Option-Hyphen and Option-Shift-Hyphen on a Mac). Or you can copy and paste from a word processor. But don’t feel obligated. If you’re in a hurry—or if it’s just not your style—you can use a hyphen (-) where an en dash (–) might be best, or two hyphens (--) or a space-hyphen-space ( - ) instead of a true em dash (—).
Q. What is correct style: “X and Y axes” or “X- and Y-axes”?
A. In the context of the Cartesian coordinate system, the hyphens are conventional: “X-axis and Y-axis” or “X- and Y-axes.” But unless the axes have been specifically labeled with capital letters, they are usually referred to as the x- and y-axes. In nonmathematical contexts (e.g., to refer to a simple chart or graph), the hyphens are often omitted, as in “x and y axes,” which has the advantage of not requiring a suspended hyphen. Consider your context and be consistent. For suspended hyphens, see CMOS 7.88; for math, see chapter 12.
Q. What combination of hyphens or en dashes is used to punctuate “a four hundred year old shipwreck”?
A. Please, no en dashes! Write “a four-hundred-year-old shipwreck.” When it comes to compound modifiers, en dashes are useful mainly for expressions that include a compound term that’s always left open: “World War II–era shipwrecks.” In your example, there’s no reason “four hundred” can’t be hyphenated and joined to the rest of the modifying phrase by another hyphen; only rarely, if ever, should a compound contain a mix of hyphens and en dashes. See CMOS 6.80 for more details.
Q. Hello, No hyphen after a number and before the word “percent”; that’s the rule, per Chicago. But if part of a longer modifier, would the following be correct? Mike said, “A 15-to-20-percent-a-year increase in sales is what’s expected.” Thank you.
A. That’s tricky, but it doesn’t need to be. Just change “a-year” to “yearly” or “annual” (and edit out the redundant “what’s” while you’re at it). Now you have “a 15 to 20 percent annual increase in sales is expected.” Or you could use an en dash in place of “to”: “a 15–20 percent annual increase . . .” (see our hyphenation guide, under “number + percent”).
Q. I’ve been having a discussion about the use of the term “water-resistant.” Chicago style dictates the use of a hyphen in such a compound only when it precedes a noun. However, the term is recognized by Merriam-Webster.
A. You’re lucky—you can’t go wrong! If you value consistency, make a note of which one you choose. Keep in mind that when such adjectival compounds follow the noun they modify, hyphenation is usually unnecessary, even for those that are hyphenated in Merriam-Webster (such as well-read or ill-humored).
Q. Does CMOS have an official position on hyphenating “the then” when used to indicate something or someone’s former status?
A. Since then is just an adjective like any other adjective, there’s no need for a hyphen.
- the current secretary of state
- the previous secretary of state
- the then secretary of state
Q. How would you treat “over apologize” in this sentence? “Be careful not to over apologize.”
A. Over is a prefix in that case, so close it up: “Be careful not to overapologize.” Please see CMOS 7.89, section 4 (“Words Formed with Prefixes”), under the prefix over.
Q. Hi CMOS—I work in mortgages, and with the increasing popularity of a “digital lending process” come electronic signatures. No one in my company can seem to agree on how to style this particular term, and as you can imagine, it comes up quite a lot. I’ve seen it four ways:
e-sign(ature)
E-sign(ature)
e-Sign(ature)
eSign(ature)
As I’m working on our in-house style guide, I’m also having to decide how it’s styled in a title or section heading of a policy document. Currently, I have eSignature as a noun and e-sign as a verb, and when it’s a verb capitalized in a title or section heading, it’s E-sign. I need to decide on four styles: (1) noun in a sentence, (2) noun in a title or at the beginning of a sentence, (3) verb in a sentence, and (4) verb in a title or at the beginning of a sentence. This is making my eyes cross. Am I good with what I have, or do you have a suggestion? I’ve consulted M-W and turned up nothing.
A. CMOS covers this at 7.89 (“Hyphenation Guide”), in section 3 under e: “Hyphenated except for email (a departure from previous editions) and certain proper nouns.” Note that capping the S in e-Signature gives it the look of a trademarked or branded product. In a title or section heading you would follow the normal CMOS style for nouns or verbs beginning with a hyphenated prefix: E-signature, E-sign. Please see CMOS 8.161.
Q. Is word-for-word hyphenated? Is side-by-side hyphenated?
A. They are both hyphenated only if they precede the word that they modify: There were side-by-side mirrors. The mirrors were side by side.
Q. If someone has a compound surname like “De Chicago-Smith,” do we use an en dash? I understand the rationale, but I think it looks weird (but who cares what I think?). What about “De Chicago-Von Suedkurve Auf Der CSS&SBRR,” for example?
A. Although a simple hyphenated name normally takes (no surprise) a hyphen, a name with multiple appendages might be able to pull off the slightly longer en dash. Anyone with such a dazzling name as “De Chicago–Von Suedkurve Auf Der CSS&SBRR” deserves all the dashes and doodads they want. (And we care what you think.)