Q. Should “cotton gin maker” have a hyphen? Does “cotton gin” here serve as an adjective, necessitating the hyphen? I’ve consulted CMOS and am still not quite sure. Thanks!
A. Good question! According to the hyphenation guide at CMOS 7.89 (see section 2, under “noun + noun, single function”), when a phrase like “cotton gin,” in which one noun (“cotton”) modifies another noun (“gin”), is used to modify a third noun (“cotton gin” modifies “maker”), the phrase would normally be hyphenated: cotton-gin maker.
That said, some editors would omit the hyphen. Not only is “cotton gin” entered as an unhyphenated noun in Merriam-Webster (with no adjective form, hyphenated or not, listed with it), but unless the surrounding context isn’t obviously relevant to cotton gins as opposed to some kind of process for making gin with cotton (whatever that would be), there isn’t much chance of confusion without the hyphen.
In sum, add the hyphen to be on the safe side, knowing that you can instead leave it out if that’s your strong preference (provided you’re consistent). In other words, this is a gray area (like the spelling of gray).
Q. I’ve been looking for a format on writing date ranges but cannot find any. How do I write a range without a death year or without a birth year? Should it be First I. Last (1804–?) or First I. Last (b. 1804)? Or is there any other way? What if you are unsure of the year because sources say different things?
A. If the person in question is no longer living, either form that you show is acceptable if all you know is a birth date: (1804–?) or (b. 1804). If the person is still living, you have the same two options (but without the question mark, and note the lack of a space between the en dash and closing parenthesis): (1984–) or (b. 1984).
If a death date but not a birth date is known, substitute a question mark for the birth date or use the abbreviation “d.”: (?–1890) or (d. 1890). To signal that a specific year of birth or death is likely but not definite, put a question mark after the year: (1804?–1890?). If the dates are contested, additional information may be provided in the text or in a note.
See also CMOS 6.68 and 6.79.
Q. Do open compounds like “face mask,” “cell phone,” “sea level,” “high school,” and “life science” (all identified as nouns by Merriam-Webster) have to be hyphenated before a noun?
A. If a compound is listed as an open (unhyphenated) noun in Merriam-Webster, and the text seems clear without a hyphen, then you can leave the hyphen out even when the noun is used attributively (and even if the rules for hyphenation in CMOS 7.89 seem to suggest otherwise):
The face mask rules did not apply to cell phone users living in areas subject to sea level rise, regardless of the number of life science courses being taught to area high school students.
That seems clear enough without any hyphens. But if you do hyphenate any one of these compounds, you should hyphenate it everywhere else that it’s been used attributively. A consistency checker like PerfectIt can make this job a lot easier. See “Hyphenation in Context: The Chicago Manual of Style for PerfectIt,” at CMOS Shop Talk.
Q. Hi! Is it ever appropriate to follow an em dash with a period if it’s the terminus of the sentence? Thanks!
A. You could try it, but there are probably better options. When an em dash marks a midsentence interruption of one speaker by another, as in quoted dialogue, it’s best not to use any additional punctuation (see CMOS 6.87):
“I thought I might—”
“Might what?”
A period after the dash would suggest that the sentence had come to an end rather than having been interrupted. But even if the speaker breaks off and then resumes speaking without a paragraph break, a period wouldn’t be necessary:
“I thought I might— Oh, it’s no use.”
not
“I thought I might—. Oh, it’s no use.”
Either option could work (and note the space after the dash in the first one), but the period in the second example makes the break seem less sudden.
Q. How would you handle “early-to-mid” + “century”? “Early to mid-twentieth century”? “Early-to-mid twentieth century”? “Early-to-mid-twentieth century”?
A. When these century phrases are used as nouns, we’d retain only the hyphen after mid: “in the early twentieth century,” “in the mid-twentieth century,” and, by extension, “in the early to mid-twentieth century.” But when they’re used as modifiers before another noun, extra hyphenation would be needed: “early twentieth-century history,” “mid-twentieth-century history,” and “early-to-mid-twentieth-century history.”
Two things to note: (1) It wouldn’t be wrong to refer to “early-twentieth-century history” (with two hyphens), but we think the extra hyphen (after early) is unnecessary (see CMOS 7.87—and note that early is an adjective, not an adverb, and therefore not subject to the -ly exception described in CMOS 7.86). (2) The word mid, unlike early, isn’t an ordinary adjective; instead, it usually combines with any word that it modifies—either with a hyphen (“mid-twentieth”) or without (“midyear”).
See also the hyphenation guide at CMOS 7.89, section 1, under “number + noun”; section 3, under “century”; and section 4, under “mid.”
Q. Working on an architecture book that uses a lot of duplex addresses—i.e., 1522-1524 Main Street. Thought it should be an en, but someone pointed out the numbers are not inclusive, as 1523 Main Street is not part of the address. Is that correct? Should it just be a hyphen? Thanks!
A. Whoever pointed out that the numbers are not inclusive has a very good point. A hyphen is the better choice than an en dash in that context.
Q. Would it be correct to use an en dash instead of a hyphen in a compound like “singer-songwriter”? What about a slash?
A. En dashes may be used in compounds referring to two different people:
Epstein–Barr virus (a virus named for two people)
Ali–Frazier fight (a boxing match between two people)
a singer–songwriter duo (referring to two people)
but
Albers-Schönberg disease (a disease named for one person)
Though Chicago doesn’t require an en dash in those first three examples, some style guides do (notably in the sciences and in British English).
But when a compound refers to only one person or thing, as in the compound nouns singer-songwriter and city-state, most styles (including Chicago) would recommend using a hyphen.
As for a slash, that’s usually reserved for alternatives, where the slash means “or” rather than “and” (as in and/or but not singer/songwriter).
Q. Hi! Would “results sharing” be hyphenated in this example? “Each webcast includes in-session polling and results sharing.” Thanks!
A. According to our hyphenation guide (at CMOS 7.89, sec. 2), a compound noun that consists of a noun plus a gerund should be left open unless listed as either hyphenated or closed in Merriam-Webster. The term “results sharing” isn’t in M-W in any form, so leave it open.
Q. Hello! I understand that hyphens work like “treatment-naive patients” but “patients are treatment naive.” However, what would you recommend if the modifier is used alone—e.g., in a graph key? Hyphen or open? Should the key be “Treatment-naive” and “Previously treated,” or “Treatment naive” and “Previously treated”? Thank you!
A. Good question! Either approach would work, but we would lean slightly toward retaining the hyphen. The words “Treatment naive” as a standalone label lack the immediate context a sentence provides, making them prone to a momentary misreading without a hyphen (as they might be before a noun).
But we’d leave “Previously treated” alone as you’ve done; that term, thanks to that ly ending, wouldn’t be hyphenated in any context.
Q. Hi. I’m working on a label for an image in a printed brochure. The entire label is “bison shoulder blade hoe.” How would you punctuate that—with an en dash (“bison–shoulder blade hoe”)? Or hyphens (“bison-shoulder-blade hoe” or “bison shoulder-blade hoe”)? I was thinking that technically an en dash would be correct according to CMOS 6.80, but that seems too formal and, as CMOS states, unlikely to be noticed by most. There is no room to reword it. Thank you!
Q. Regarding open compounds, would an en dash be correct in “Mr. Potato Head–like head” and “rubbing alcohol–soaked cotton”? Thank you!
A. See CMOS 7.85: “With the exception of proper nouns (such as United States) and compounds formed by an adverb ending in ly plus an adjective (see 7.86), it is never incorrect to hyphenate adjectival compounds before a noun.” The goal of adding such hyphens is to clarify the meaning of the text.
To start with the bison, that example refers to a hoe fashioned from a bison’s shoulder blade. The three relevant terms are bison, shoulder blade, and hoe, so the clearest version is the last: “bison shoulder-blade hoe.”
We agree that an en dash wouldn’t work all that well; in “bison–shoulder blade hoe,” readers would need to recognize “shoulder blade” as a distinct compound before “hoe.” You’d be better off leaving the words open (“bison shoulder blade hoe”), trusting readers to sort out the modifiers without the help of hyphens or dashes. Or you could use two hyphens (“bison-shoulder-blade hoe”), but that doesn’t single out “shoulder blade” either, so the uncluttered open version is better.
As for the second question, it would be hard to improve on “Mr. Potato Head–like head,” where the en dash provides a perfect illustration of the principles covered in CMOS 6.80. And though the en dash is technically correct also in “rubbing alcohol–soaked cotton,” we’d advise rephrasing: “cotton soaked in rubbing alcohol.” Readers then won’t have to mentally sort out the string of modifiers to identify “rubbing alcohol,” a compound that, like “shoulder blade” in the bison example, lacks Mr. Potato Head’s prominent initial caps. Nor would “rubbing-alcohol soaked cotton” work; participles like “soaked” always require a hyphen in that position (see the hyphenation guide at CMOS 7.89, sec. 2, under “noun + participle”).