Q. Hello! I work as a proofreader in retail, and we often use “on sale” in headlines. I’m not sure if “on” is acting as a preposition or an adverb, therefore I’m not sure if it should be capitalized in a headline like this: “Now on Sale.” Thank you!

A. In “on sale,” on is a preposition and sale is its object. The expression itself is a phrasal adjective. Your headline is shorthand for “This Item Is Now on Sale” (or “These Items Are Now on Sale”)—in which the phrase “on Sale” modifies the understood item (or items). Chicago’s exceptions to its rules for headline-style capitalization do not extend to the use of prepositions in phrasal adjectives (except in common Latin phrases like “de facto”). So to follow Chicago style, write “Now on Sale.” See CMOS 8.159.

Q. Is the hyphenation in the following sentence incorrect, or is it just not Chicago style? “He had only two seasons with twenty-or-more homers.” Thanks for another great year of Q&A!

A. The hyphens in “twenty-or-more homers” are contrary to Chicago style and also incorrect. The phrase “twenty or more” describes two separate quantities; hyphens would illogically suggest a single quantity of “twenty-or-more.” On the other hand, hyphens are helpful (and strictly Chicago style) in a phrase such as “two twenty-or-more-homer seasons”—though “two seasons with twenty or more homers” is easier to read.

Q. I just bought the 17th edition. Do you know where I can find out what typeface the text is set in?

A. If you turn to the very last page of text, following the index, you will see that the print edition of the Manual is composed (or typeset) in Lyon and Atlas Grotesk. Lyon, which has serifs, is used for most of the text aside from run-in paragraph subheads and certain illustrations. (The statement at the end of the book about design and production is called a colophon; see CMOS 1.67.) To complement the look of the printed book, CMOS Online (including the Q&A!) uses a version of Lyon designed for the screen.

Q. In your hyphenation table (CMOS 7.89), why is “mid-twentieth” in “mid-twentieth century” hyphenated? Shouldn’t it be closed up as “midtwentieth century” or have an en dash instead of a hyphen?

A. That’s a good question! The fourteenth edition (1993) did advise an en dash: “mid–twentieth century.” But we decided as of the fifteenth (2003) that this was just too fussy. The hyphenated form lends itself better to compound modifiers, as in “mid-twentieth-century furniture.” So when the less common noun phrase is used, we prefer to retain the hyphen: “mid-twentieth century.” A similar logic has discouraged us from advising “midtwentieth century”—though we do recommend “midcentury.”

Q. Would you ever use “styleguide” as a single word?

A. Probably only in a hashtag—#StyleGuide or #styleguide (hashtags aren’t case sensitive, and Chicago style allows for either). Guide, unlike book, doesn’t tend to form one word unless it’s at the beginning. So style guide but stylebook and guidebook. For answers to questions like this one, Merriam-Webster is our go-to guide.

Q. Where does an emoji go in a sentence? Before or after the period? ✏️ Having a tough time deciding 🤔.

A. An emoji that applies to a sentence as a whole might logically follow the period or other terminal punctuation. Let’s coin a term and call this a sentence emoji. 😉 Then, by a similar logic, emoji applying to a word or a phrase could immediately follow that word or phrase, before any mark of punctuation 🔍, like that. Emoji standing in for words, like this picture of a 🐈—well, you get the idea. But like if you’re texting? Most of this logic goes out the window (along with the punctuation). Love your emoji btw!

Q. Doesn’t “The US is the second-largest carbon dioxide emitter after China” make it sound like the US is actually the third-largest carbon dioxide emitter? I see these formulations, which include [number] plus [superlative] and a direct comparison, often, and they seem confusing. Wouldn’t it make more sense to say “The US is the largest carbon dioxide emitter after China” or “The US is the second-largest carbon dioxide emitter; China is the largest”?

A. You’re right: if you think about it for more than three or four seconds, that sentence is less than perfectly unambiguous. But no one would describe the third-largest emitter as the second-largest emitter after the second-largest emitter! This is an example of a convenient and harmless shorthand—where “after” means something like “trailing only.” And it’s a helpful shorthand: not only is it concise, but it also prevents the momentary ambiguity inherent in your first solution (“The US is the largest carbon dioxide emitter . . .”). Note that a comma, though typically omitted from “nth-largest . . . after . . .” constructions, would provide useful clarification before the prepositional phrase “after China”; before the participial phrase “trailing only China,” such a comma would be required (see CMOS 6.30).

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. When is a line space in text (pause) used?

A. A blank line usually signals any break that is stronger than a paragraph but not strong enough to warrant a subhead. In novels and other creative works, such breaks may signal a new narrative voice or a change of location or a leap in time (either forward or backward). There’s no limit to how they can be used, but a good editor will point out breaks that seem arbitrary or distracting. You will also need to be prepared for the fact that a blank line occurring at the end of a page may not read as a break; asterisks or a similar device may be needed. See CMOS 1.58.