Trade Tool: Hyphenation Tables

Trade Tools for Academic Editing

Many of the tools I use as a professional academic editor could be used (and well!) by thoughtful writers and revisers, so I’ve decided to start featuring some of the handier implements and resources that are part of my editing routine.

This first one I actually keep in my dock. (That’s the menu bar across the bottom of my Mac’s desktop.) It’s The Chicago Manual of Style’s hyphenation table. Found in chapter seven of the big orange book, the chart summarizes Chicago’s logic regarding compounds and provides very specific examples.

Hyphenation Table for Academic Editing

Let me back up for a second: Chicago has a few foundational guidelines for the treatment of compounds (to hyphenate or not?). First, recognize that compounds tend toward closure. As it becomes more common, a term that’s open (“data base”) will probably become hyphenated (“data-base”) and then eventually close completely (“database”).

Second, a compound modifier appearing before the term (usually a noun) that it modifies tends to be hyphenated: “at-risk students” versus “students at risk.” Those are the most important general trends to be aware of in order to treat compounds according to Chicago style.

The hyphenation table itself contains four main sections:

  1. compounds according to category
  2. compounds according to parts of speech
  3. compounds formed with specific terms
  4. words formed with prefixes

So you want to know how to handle a fraction? Section 1 includes “fractions, compounds formed with” and “fractions, simple.” There, we find examples such as “one and three-quarters” and general rules. Compounds formed with fractions (“quarter-hour session”) are open in noun form and hyphenated as adjectives. Simple fractions are hyphenated all the time unless the second element is already hyphenated.

Those are easy guidelines to follow.

Maybe we want to know whether to hyphenate a compound starting with the prefix “semi.” Section four provides examples that make aesthetic sense: “semiopaque, semiconductor, but semi-invalid.” Of course! “Semiinvalid” would just look strange and would probably cause a reader to think twice, which impedes a composition’s flow.

What about “widely used”? Would that be hyphenated before a noun? Section 2, compounds according to parts of speech, has a listing labeled “adverb ending in ly + participle or adjective.” There, we learn that such terms are never hyphenated, regardless of position: “widely used text,” “text that is widely used.”

I could go on and on. I honestly refer to this table multiple times each day. Because I know Chicago’s general guidelines for hyphenation, I usually know how to handle the compounds that arise, but I like to verify my hunches.

If you have a personal subscription or access to CMOS online through your university library, I suggest you visit and download the chart for quick reference. (Here’s the direct link, or you can go through your library website to access it.)

APA holds to similar principles and provides examples more germane to the social science, but I haven’t seen a digital version of the Publication Manual’s charts. The APA Style website addresses hyphenation here.

MLA also weighs in on the hyphenation discussion, and again the guidelines resemble Chicago’s. The examples differ (sometimes helpfully), and the explanations are less thorough.

That’s often the case: Chicago’s treatment of a style issue is more detailed than can be found in other guides. That’s why I rely on my handy PDF of Chicago’s hyphenation table.

One more thing: you can always look up a specific term in the dictionary, but remember that hyphenation is often advised when a compound modifier appears before what it modifies, but modifiers appearing after what they modify are often left open. The dictionary, then, isn’t a perfect guide.

That’s today’s trade tool. I hope you see the value of a hyphenation table and consider using one as you write and revise your next project.

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