Hyphens, En Dashes, Em Dashes

A. Chicago hyphenates all “free” words in any position: toll-free call; the call was toll-free. See 7.85, section 3, under “free.”

A. I will try to condense the various bits of information scattered throughout CMOS. First of all, there are three lengths of what are all more or less dashes: hyphen (-), en dash (–), and em dash (—). I frame it this way because the work they do is roughly related to their length (though I don’t think CMOS puts it this way outright).

The hyphen connects two things that are intimately related, usually words that function together as a single concept or work together as a joint modifier (e.g., tie-in, toll-free call, two-thirds).

The en dash connects things that are related to each other by distance, as in the May–September issue of a magazine; it’s not a May-September issue, because June, July, and August are also ostensibly included in this range. And in fact en dashes specify any kind of range, which is why they properly appear in indexes when a range of pages is cited (e.g., 147–48). En dashes are also used to connect a prefix to a proper open compound: for example, pre–World War II. In that example, “pre” is connected to the open compound “World War II” and therefore has to do a little extra work (to bridge the space between the two words it modifies—space that cannot be besmirched by hyphens because “World War II” is a proper noun). Now, that is a rather fussy use of the en dash that many people ignore, preferring the hyphen.

The em dash has several uses. It allows, in a manner similar to parentheses, an additional thought to be added within a sentence by sort of breaking away from that sentence—as I’ve done here. Its use or misuse for this purpose is a matter of taste, and subject to the effect on the writer’s or reader’s “ear.” Em dashes also substitute for something missing. For example, in a bibliographic list, rather than repeating the same author over and over again, three consecutive em dashes (also known as a 3-em dash) stand in for the author’s name. In interrupted speech, one or two em dashes may be used: “I wasn’t trying to imply——” “Then just what were you trying to do?” Also, the em dash may serve as a sort of bullet point, as in this to-do list:

—wash the car

—walk the dog

—attempt to explain em and en dashes

This explanation is not intended to be exhaustive (for much more, see chapter 6 in CMOS 16), but I do hope that it helps to frame the different potential of each length of dash.

A. You have it right. The idea is that you are “developing short-term, medium-term, and long-term steps for” something, but that you want to avoid repeating “term,” so you simply delete the first two instances of “term”; et voilà: now you are “developing short-, medium-, and long-term steps.”

A. I think an analogy is appropriate, here. Canton is in Ohio. Therefore, Canton, Ohio. The University of California’s East Bay institution is in Berkeley, California. So, it’s the University of California in (or at) Berkeley, or the University of California, Berkeley. I can see an en dash being used as well, because an en dash can join one word to a compound, as in “a jazz–rock ’n’ roll hybrid” (where the en dash joins “jazz” to “rock ’n’ roll”). Berkeley needs to be joined to the entire “University of California,” so an en dash would work, but not a hyphen. By the way, the University of California prefers the comma.

A. All prefixes form words that are closed unless the word it is joined with is a proper noun, or if there would be ambiguity owing to, for example, a doubled letter, or if the hyphenated version is in the dictionary:

autoloading

auto-destruction [hyphenated, I would suppose, because it is analogous to self-destruction]

autobus

auto-ovulation [to avoid double o]

auto-Nietzschean

A. CMOS prefers the actual minus sign, which is not the same as an en dash, in professionally typeset material. The minus sign is defined by Unicode as U+2212; the en dash is U+2013. See CMOS, paragraph 11.2 and table 12.1, for more information.

A. Usually, a hyphen is unnecessary: write “five feet two inches tall,” “five feet two inches,” “five foot two,” and so forth. But a hyphen is helpful in expressions such as “five-two.” If you write 5′2″, there’s no space after the sign for feet (a prime symbol). See CMOS 7.85, section 1, under “number + noun.” See also 10.69.

A. Dear Missouri: You are correct. In a phrase such as “a five-year-old,” the age modifies an implicit noun. See 7.85, section 1, under “age terms,” for more examples.

A. Write “foreign-policy-making elite.” See 6.80 for some analogous examples.

A. The CMOS rule, which you can find at paragraph 7.82 of the sixteenth edition, is to leave such compounds open. An ly strongly signals adverb—and adverbs cannot modify nouns by themselves. No hyphen is needed, then, to warn that the next word is not a noun but rather an adjective. There’s no such thing as “an explicitly rule,” so there is no chance of misreading “explicitly defined rule.”

That said, it has long been the practice elsewhere—among British writers, for example—to hyphenate ly + participle/adjective compounds. And American writers a century ago—Edith Wharton comes to mind (“the pallour of her delicately-hollowed face,” describing an exhausted Lily Bart toward the end of The House of Mirth [1905])—seemed always to use such hyphens (or at least their publishers did). The reasoning behind this approach may be that the ly so strongly telegraphs another modifier that the two might as well tie the knot.

So it is a matter not of who is right or wrong but of whose rule you are going to follow. We think that added to our logic is the small victory of avoiding a hyphen.