Q. I am editing a brief in which the author has used “and/or” multiple times. I know that this term should be avoided, but I’m not exactly sure why. Is it because it’s confusing and ambiguous? What is The Chicago Manual of Style’s stance?

A. CMOS, in chapter 5, says to “avoid this Janus-faced term” (5.250, s.v. “and/or”). Janus-faced means duplicitous—in other words, appearing to say two contradictory things simultaneously. The problem is the slash, which is potentially ambiguous; for example, readers might choose to interpret “x and/or y” as meaning either x and y or just y—but not x alone. In fact, “x and/or y” is usually intended to mean “x or y, or both,” and where that is the case, section 5.250 recommends writing exactly that (take a sleeping pill or a warm drink, or both). In many cases, however, “or” alone would make the meaning perfectly clear. For example, “no cats or dogs allowed” means that no combination of cats or dogs—or cats and dogs—is allowed. In formal prose, including legal writing, such considerations of the precisely intended meaning are important. In casual prose, “and/or” can occasionally serve as a useful shorthand: bring your own beer and/or wine. No one will fail to understand the meaning of that.

Q. When a question introduces a list, should you use a question mark or a colon? Or both?

A. First, don’t use a question mark immediately followed by a colon, or vice versa (neither :? nor ?:); instead, use the stronger mark. Assuming a direct question, the question mark is usually stronger.

Which fruit would you be most likely to recognize by texture alone?

banana
apple
blueberry
cherry
pineapple

A signal like “the following” can be helpful in such cases: “Which of the following fruits . . .”

If you incorporate the list into a sentence, the question mark can follow the last item.

Which fruit would you be most likely to recognize by texture alone: bananas, apples, blueberries, cherries, or pineapples?

Especially for shorter sentences, a comma can be used instead of a colon to introduce the list.

Which fruit do you like best, bananas or pineapples?

but

Do you prefer apples or bananas or blueberries? [See CMOS 6.67.]

Q. Hello! I have a comma question. Which is the preferred punctuation: Amherst, Massachusetts’ Emily Dickinson . . . OR Amherst, Massachusetts’, Emily Dickinson . . . ? Recasting the sentence is not a useful option because there is a longish list of names and places: Long Branch, New Jersey’s Bruce Springsteen and Lachine, Quebec’s Saul Bellow and . . . Thanks.

A. Rewriting to avoid the possessive is (almost) always an option; that’s what “of” is for. Try “Emily Dickinson of Amherst, Massachusetts; Bruce Springsteen of Long Branch, New Jersey; etc.” Parentheses are another useful alternative: “Emily Dickinson (Amherst, Massachusetts)” (or vice versa). But if you must stick to the possessive, you have our permission to drop the second comma (the one after the state or province) as a reasonable exception to Chicago’s preference for commas in pairs, a preference that applies also to dates (see CMOS 6.17 and 6.38–39). Note that Chicago style for the possessive form of Amherst’s home state requires an apostrophe and an s: Massachusetts’s Emily Dickinson (another incentive to avoid the possessive).

Q. Now that Merriam-Webster has legitimized the singular “they,” where does CMOS stand on the subject?

A. First, please note that there are two uses for the singular “they,” generic and specific. In 2019 Merriam-Webster added a specific sense of singular “they” to refer to a person who does not identify with a gender-specific (or binary) pronoun (“A Note on the Nonbinary ‘They’: It’s Now in the Dictionary,” Merriam-Webster, September 19, 2019). This use of “they” was recognized in the 17th edition of CMOS, published in 2017 (see paragraph 5.48). So Chicago and Merriam-Webster are in sync on that.

Singular “they” is also used as a generic pronoun referring to a person of unspecified gender, an established usage that nonetheless has long been considered informal. As of the 17th edition, CMOS recognizes that such usage is gaining acceptance in formal writing but still advises avoiding it if possible—for example, by rewriting to use the plural (see CMOS 5.255). Generic singular “they” has been around for a long time, however, and most editors here at Chicago have no problem with such constructions as everyone should bring their favorite book to the event—where “their” refers back to the indefinite (and usually singular) pronoun “everyone.” And many of us have come to accept less firmly established usages such as each programmer worked in their preferred language. Like it or not, “they” has been displacing “he or she” and similar attempts to write around the English language’s lack of a dedicated gender-neutral singular pronoun for some time now. Stay tuned for further developments.

Q. In the sentence “It happened on the twenty-fourth of July,” should the date be spelled out or a numeral? CMOS 9.31 only addresses the treatment of ordinals when the month is not mentioned.

A. We get this question a lot. Let’s start with the conventional formats—July 24, 2020 (typical US style); 24 July 2020 (typical style outside the US); 2020-07-24 (ISO style). Each of these uses a cardinal rather than an ordinal numeral for the day, whether the year is expressed or not (i.e., July 24 or 24 July, not July 24th or 24th July). Outside of these conventional formats, our recommendation would be to spell out ordinals for the day of the week even when the month is mentioned: the twenty-fourth of July; the twenty-fourth (but the Fourth of July or the Fourth for the US holiday; see CMOS 8.89). But keep in mind that this rule applies primarily to formal, long-form prose—so it’s possibly a little too formal for many contexts; if you prefer numerals, or if you need to use them to save space, you have our blessing (the 24th of July, or the 24th). And if you follow Chicago’s alternative system of spelling out only one through nine, an all-numeral approach for days will facilitate consistency (e.g., we’ll be offering tours on the 1st, 2nd, and 24th of July).

Q. Would you use “less” or “fewer” with “CO₂ emissions”? To me, “emissions” seems like a measurable, uncountable substance, so I would say “less.” However, a quick search on Google Ngrams shows “fewer emissions” is more common. Which is correct? Or should it be “lower” instead? And if so, why?

A. Your preference for “less” makes a lot of sense. In formal writing, however, “fewer” has long been preferred with a plural noun, no matter how difficult it might be to count. According to that preference, if it takes a plural verb, you would use “fewer”: so, fewer CO₂ emissions, but less CO₂ (carbon dioxide is a mass—or noncount—noun: CO₂ is; CO₂ emissions are). It may be helpful to consider the case of “data.” Even though “data” doesn’t look like a plural, you would write “less data” or “fewer data” depending on whether you consider “data” as a mass noun (as in common usage) or as a plural (as in the sciences).

We had a lot less data to support our hypothesis than we wanted. [data as mass noun]

but

The second group of researchers returned fewer data than the first. [data as a plural noun]

The latter usage—including the use of “fewer”—is supported by the AMA Manual of Style (10th ed., sec. 7.8.2). In other words, the data support(s) “fewer emissions.”

The alternative “lower emissions” can also work. Unlike temperatures or costs, which can be higher or lower in the singular or the plural, we don’t normally talk of a higher or lower emission singular. But we do talk of higher or lower emissions plural—where “level(s)” is understood. And an Ngram comparison of “fewer,” “less,” and “lower” as adjectives modifying “emissions” (adding “_ADJ” to a term filters out other parts of speech) shows that “lower emissions” is more common than the other two phrases combined.

In sum, “fewer” is considered to be correct, but “lower” is a good alternative—and well established. Meanwhile, though “less emissions” seems like a rational choice (it’s unambiguous, and it has the advantage of being the shortest option), avoid it if your goal is to satisfy any sticklers.

Q. In a recent Q&A the hyphens look like en dashes to me. Are they, and if they are, why?

A. You must be referring to the main entries for “fund-raiser” and “fund-raising” in the screenshot from the first printing of the 11th edition of Merriam-Webster’s Collegiate Dictionary. Those do look like en dashes, but they are presented that way for maximum legibility: for one thing, regular hyphens might be confused with the centered dots that indicate places where a hyphen may be added to divide a word at the end of a line. In other words, “fund–rais·er” is easier to interpret at a glance as a hyphenated term than “fund-rais·er” would be. For what it’s worth, at Merriam-Webster.com, the hyphens in main entries are really hyphens. For the entry words online, however, M-W uses the font Playfair Display, which has the advantage of featuring generously long hyphens. This matters a bit less in the online version of the dictionary, where suggested word division is shown on a separate line, below the main entry (and in a different font that happens to feature shorter hyphens). But as this screenshot from the definition for “self-conscious” shows, the extra-long hyphen is strikingly legible: