Q. When using a preceding -ly adverb to modify an adjective, it typically pains me to use an open form (no hyphenation). But I bite the bullet, follow CMOS, and eliminate the hyphen. Yet when there are two essentially equivalent formulations where one adverb is an -ly adverb and the other is not, I’m perplexed as to the logic. For instance: She had a nearly encyclopedic knowledge of baseball statistics versus She had an almost-encyclopedic knowledge of baseball statistics. Can you provide any insights? Thank you.
A. Okay, so you have a deeply-rooted dislike—as Jane Austen’s publisher styled that phrase in the 1813 first edition of Pride and Prejudice, vol. 2, p. 124—for the modern rule that says that you should write deeply rooted dislike (as covered in CMOS 7.96, section 2, under “adverb ending in ‑ly + participle or adjective”). We’re not offended. The idea that readers will expect an adjective rather than a noun after a word like deeply and thus don’t need any help from a hyphen could easily be turned on its head. You could argue instead that the adverb and participle clearly belong together and should go ahead and tie the knot (with a hyphen).
But if you do follow Chicago style, don’t worry about being inconsistent in the examples you cite. Our editors would tend to leave the compound modifiers in both of your sentences open: a nearly encyclopedic knowledge and an almost encyclopedic knowledge. See CMOS 7.96, section 2, but this time under “adverb not ending in ‑ly + participle or adjective,” which notes that “certain compounds, including those with more, most, less, least, and very, can usually be left open unless ambiguity threatens.”
As one of the examples in that category suggests (“a rather boring play”), you can extend this exception to other adverbs of degree, including not only rather but also almost.
We’ll make a note to consider clarifying this in a future edition of CMOS. It’s less likely, however, that we’ll be revising our rules to be more in line with nineteenth-century hyphenation conventions.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. When using a letter + noun, should there always be a hyphen, never be a hyphen, or something in between? Specifically, something like “k value” or “k curve”?
A. According to section 5.4.1.2 in the ninth edition of The CSE Manual (published in 2024 by the Council of Science Editors in cooperation with the University of Chicago Press), letters that are used in scientific terms as modifiers can remain unhyphenated except when the term itself is a modifier before a noun: “S curve” but “S-curve characteristics.” You’ll also find “S curve” as an example in CMOS, under paragraph 7.70.
You’d also want a hyphen when the letter is paired with a participle before another noun, as in “k-shaped curve,” an expression that works better with a capital K, whose diagonal strokes more clearly suggest the idea of a graph with diverging values: “K-shaped curve.”
There are some exceptions. For example, we would refer to the “x-axis” (following Merriam-Webster—except for the italics, which aren’t usually shown in dictionary headwords; we italicize the label because it derives from the mathematical variable x). Another exception is “x-ray,” which is hyphenated as a matter of established usage and often spelled with a capital “X” (but without italics, maybe because the letter simply meant that the type of radiation was a mystery when it was first described, as suggested under “Word Origin” in Merriam-Webster’s entry for the term and by the term’s etymology in the OED).
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. The hyphenation guide at CMOS 7.96 (in sec. 2, under “adjective + noun”) lists “a top-ten school” as containing a compound modifier that needs a hyphen. But would “top ten” always be considered a compound modifier when it appears in front of a noun? For example, in the case of “the top ten schools on the list” (or any construction of “the top ten schools”), would you still recommend hyphenating?
A. That’s a very good question! A top-ten school means a school that is among the top ten schools on a ranked list. In the first expression, top-ten is a compound modifier and is therefore hyphenated; in the second, the phrase top ten simply means first ten, so no hyphen is needed.
Only rarely would the phrase the top ten schools need a hyphen, as when top-ten is being used as a category—a scenario that would be more likely with singular school: Harvard, the top-ten school most commonly selected by students planning to major in political science, is in Cambridge.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. I know that there’s a rule that says if two adjectives can be joined by the word and without affecting the meaning, then you should separate the two adjectives with a comma. But sometimes a hyphen seems like the better choice. For example: “a historical-philosophical context” or “military-political involvement.” Do you agree?
A. The hyphens in historical-philosophical and military-political imply a mix of factors that’s more complex than what and would suggest—more of an intersection than a pair of attributes. If that’s what you intend, keep the hyphens rather than replacing them with commas.
These adjectives are equivalent to a term like socioeconomic, in which the word social in social-economic has become the combining form socio- and joins with economic to become one word (some of these terms retain their hyphens; see CMOS 7.96, sec. 2, under “combining forms”).
In fact, the similar term historicophilosophical is entered in Wiktionary and makes an appearance as an example under historico- in Merriam-Webster, so you could consider using that form instead of historical-philosophical (though you could retain the hyphen in this unwieldy compound for the sake of legibility: historico-philosophical).
There’s no established combining form for military, but military-political works well. Or you could try politico-military, as entered in Wiktionary.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. Should a compound modifier be hyphenated if the noun does not immediately follow? For example, “Hand fabricated in 18-karat yellow gold circa the mid-19th century, the intriguing jewel connects by way of a . . .” “Hand fabricated” is the modifier.
A. When a compound modifier that would normally be hyphenated before a noun that it modifies (hand-fabricated jewel) is separated from that noun by an intervening phrase, keeping the hyphen is usually best. In your example, a hyphen will prevent readers from thinking, however fleetingly, of a hand fabricated in gold (as on a statuette 👋).
Plus, the phrase hand fabricated is closely analogous to handmade and handcrafted, both of which are entered as one word in most dictionaries. It’s also like hand-painted, which is entered as a hyphenated adjective in both Merriam-Webster and the OED. This suggests that hand fabricated, though it’s not in most dictionaries, naturally forms a unit and could benefit from a hyphen no matter where it appears in a sentence.
In other words, you might consider retaining a hyphen for this term even when it follows the noun it modifies—that jewel is hand-fabricated—though Chicago style allows you to omit it there (see CMOS 7.92 and “Compound Modifiers After a Noun: A Postpositive Dilemma,” at CMOS Shop Talk).
In general, be sparing with your hyphens, which can add unnecessary clutter to your prose. But any hyphen added (or retained) for the sake of clarity is usually a good idea.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. Per paragraph 7.92 in CMOS, some compound adjectives keep a hyphen even after a noun, including compounds with “ill” (also covered under “ill” in the hyphenation table). For example, we could be correct in writing this: “The scene was ill-described.” In cases where the compound is not in play, I assume we stick to dropping the hyphen, since we’re now working with just an adverb + verb. For example: “Gruesome ill described the scene.” Is this correct? I suspect I’m overthinking things. (Revising the sentence beyond mechanical correctness is out of the question in this client’s case.)
A. Though CMOS doesn’t cover this specific case, common sense does suggest that you wouldn’t need a hyphen when an adverb is paired with a past participle used as a verb rather than as an adjective. You could try substituting a different adverb for ill to test this hunch: “Gruesome now described the scene.” A hyphen would be out of place there.
But the wording in your sentence is unusual—ill is rarely paired with verbs other than afford, treat, or use—so hyphenation might be helpful. The expression ill afford is in Merriam-Webster without a hyphen, but that phrase generally has only one form: can (or could) ill afford. By contrast, both ill-treat and ill-use are entered as hyphenated verbs, giving you a couple of models to follow.
Verdict? A hyphen in your example, though not strictly required (see also CMOS 7.96, sec. 2, under “phrases, verbal”), may help clarify that ill belongs with the verb. You could add one (“Gruesome ill-described the scene”) unless your client prefers otherwise.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. What is the rule on hyphenating multiple colors? For example, it would be “a black-and-white photo,” but you never see any other color combinations hyphenated (like “a pink-and-yellow scarf”).
A. Putting something in black and white has been a thing for centuries; according to Merriam-Webster, the noun phrase black and white to mean writing or print dates to 1569. Once color photography became popular, the adjective black-and-white—with hyphens—was probably inevitable.
A pink-and-yellow scarf, on the other hand, or one that’s red and white or blue and green or any other combination you can think of? Those are arbitrary combinations. But you should hyphenate any one of them as a preceding modifier regardless (as at the start of this paragraph), at least if you’re following Chicago style. Hyphens will make it more obvious that you aren’t referring, for example, to a pink and a yellow scarf.
This issue is not, however, black and white. For more on this subject (including why we’ve left the hyphens out of black and white in the first sentence of this paragraph), see “Compound Modifiers After a Noun: A Postpositive Dilemma,” at CMOS Shop Talk.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. Why doesn’t the 18th ed. website have a downloadable PDF of the hyphenation guide, as the previous editions had? I hate scrolling.
A. The hyphenation guide under CMOS 7.96 in the eighteenth edition consists of HTML text formatted as a table, which is visible to the Find feature in browsers (unlike the PNG offered in the seventeenth edition) and is considered by accessibility experts to be preferable to PDF.
We understand that many people liked the downloadable PDF option, but the HTML table format (unlike either an image or a PDF file) can be readily converted to whatever format you’d like. Here are two options:
1. Print to PDF. In Chrome for Windows, (a) select the table text (e.g., by dragging your mouse from the top left of the table all the way down to the bottom); (b) right-click anywhere in the selected text to bring up the context menu; (c) choose Print; and (d) change Destination to Save as PDF instead of sending the table to a printer. Before you save, you can adjust the settings in Chrome to resize the table as desired or to keep the background graphics (in this case shading), among other options. Other browsers and platforms will have similar options.
2. Copy and paste into Microsoft Word. Select the table text as in step 1a above and then copy and paste it into Word. You can then use Word to adjust fonts and borders and the like as desired. This file can be used as is, or you can save it as a PDF directly from Word. These steps should work equally well in Google Docs (among other programs).
In sum, the HTML format for the table in the eighteenth edition makes it possible to create and customize your own PDF or other version of the hyphenation guide in just a few steps. The process may not be as much fun as making a miniature CMOS ornament, but the result is probably more useful.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. I’m editing a list of security recommendations. Would you put a hyphen in “password-protect” when used as a verb?
A. According to the hyphenation guide at CMOS 7.96 (sec. 2, under “phrases, verbal”), compound verbs like that one are left open unless entered in Merriam-Webster with a hyphen. There’s no entry there for that verb, hyphenated or otherwise, so we’d write password protect.
If you strongly prefer the hyphen, you could cite the OED, which does include an entry for the term, where it’s hyphenated (password-protect). The OED mostly reflects British usage, but many similar verbs are listed in either Merriam-Webster or the OED with a hyphen (e.g., double-click, fact-check, hot-wire, fast-forward). And though the term password-protect isn’t listed in either Microsoft’s or Apple’s style guide, the similar verb write-protect is listed in Microsoft’s guide (and in the OED) and copy-protect is entered in Apple’s guide (all as of February 3, 2026).
In sum, Chicago style would call for password protect (no hyphen), but the hyphen is nonetheless a reasonable choice recorded in at least one major English-language dictionary and reflected in similar terms.
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]
Q. Would you please confirm that “over the top” is not hyphenated when used as a predicate adjective or adverbial phrase. Example: “It’s extreme,” she said. “Way over the top.”
A. We can confirm that Chicago style doesn’t require hyphens in over the top when it’s used as a predicate adjective (as in your example, where it modifies the implied subject “It” from the previous sentence) or when it’s used an adverb (“they went over the top with their demands”). But you won’t necessarily get this answer from the dictionary.
Merriam-Webster’s entry for that term shows two forms: the phrase over the top (without hyphens) and the adjective over-the-top (with hyphens). That hyphenated adjective, however, isn’t the last word.
In Merriam-Webster’s entries for over-the-top and many other hyphenated compound adjectives, the hyphens are generally presented as if they’re a permanent fixture of such terms. But more than a few of these terms—from clear-cut to well-versed—can be left unhyphenated when they follow rather than precede a noun that they modify, a usage long supported by CMOS. For example, you could refer to “an over-the-top solution” (with hyphens) but “a solution that was over the top” (no hyphens).
This nuance may be falling out of fashion (perhaps because it’s so easy to toggle over to the dictionary for any hyphenation question and copy whatever’s entered there), but it still matters in Chicago style. For more on this subject, see “Compound Modifiers After a Noun: A Postpositive Dilemma,” at CMOS Shop Talk. See also the hyphenation guide at CMOS 7.96, under “phrases, adjectival”; for adverbs, see “phrases, adverbial.”
[This answer relies on the 18th edition of CMOS (2024) unless otherwise noted.]