Appendix 11: Clarification on Hyphenation Rules
Confused about whether to hyphenate a compound term? First look at the house style sheet. We have exceptions to Webster’s rules (e.g., weightlifting, powerlifting, deadlift). If the term you’re looking for isn’t on the house style sheet, consult table 6.1 (pages 229 to 231) of the 14th edition of Chicago Manual of Style or sections 7.82 to 7.90 on pages 299 to 308 of the 15th edition for guidelines on hyphenation. If the term you’re looking for doesn’t appear in those sections, or if those sections don’t address your question, consult the dictionary.
Hyphenation With Prefixes
It’s safe to say that most every prefix is closed up with the root word (e.g., overorganized, underrotated, preparticipation, preseason, semiopen, semifinal, quarterfinal, preexisting). Table 6.1 (14th edition) and pages 306 to 309 (15th edition) of CMS list examples and some exceptions. Authors commonly hyphenate or leave open prefixes with root words, so be aware of CMS conventions when you encounter hyphenated or open prefixes in a manuscript. To clarify your decisions for future workers and to ensure consistency, list your hyphenation decisions on your style sheet. You can include a general note at the beginning of your style sheet; here’s an example:
Close up all compounds with "pre"; exceptions are noted in the list of terms.
Watch for homographs (e.g., "recreate" means to give new life or freshness to; "re-create" means to create again). Some compunds that seem logical as closed-up words or open compounds are hyphenated (e.g., mind-set, stepping-stone). Get accustomed to consulting the dictionary. (Merriam-Webster has their 10th edition published on their Web site, which makes it easy to consult while you’re editing online. Here’s the link: www.m-w.com/home.htm)
Hyphenation With Adjective and Noun Compounds
This is where the rules get sticky. Do I hyphenate weight training program? What about world class athlete? real estate agent? health care worker? high intensity? decision making? decision making skills?
CMS, particularly the 15th edition, gives guidelines on these matters. I’ll just summarize my expectations here.
Easily Recognized Versus Ambiguous Compound Terms
Terms such as real estate agent and health care worker (or any combination with health care) are familiar compound nouns to almost everyone, so leaving these terms as open compounds wouldn’t cause much confusion to the reader. We commonly have terms such as weight training program and resistance training program in our books. Trade copyeditors tend to hyphenate those terms, whereas academic editors tend to leave those open. You can leave those terms open, regardless of the type of book you’re working on (whether it’s trade, HPERD, or STM, or distance education).
Terms such as high-intensity program, two-week session, and two- and three-week sessions require hyphens because, without them, readers can get misled or confused. High program or intensity program doesn’t make sense; high-intensity is the compound adjective modifying the noun, so it must be hyphenated. Same principle applies to two- and three-week program. Neither the term two program nor week program makes sense, so you need hyphens to join the the numbers (two and three) with the word week to form a compound adjective modifying program.
Predicate Compound Adjectives Versus Compunds Before the Noun
Learn the distinction between these two types of adjectives. A compound adjective with a participle (i.e., a verb that ends in "ing" or "ed") is hyphenated when it’s before the noun it modifies (but see exceptions in the previous section); it is not hyphenated when it’s after the noun (i.e., a predicate adjective). Here are some examples:
The class is age segregated. (pa)
I’m in an age-segregated class. (before noun)
His performance was world class. (pa)
He gave a world-class performance. (before noun)
She has good decision-making abilities. (before noun)
Decision making is not one of her talents. (gerund noun as subject)
She’s taking graduate-level classes. (before noun)
Her classes are graduate level. (pa)
Copyeditors, please indicate the distinctions of predicate adjectives and adjectives before nouns on your style sheets!
When to Use En Dashes
The en dash is used in place of a hyphen in a compound adjective when one of its elements is an open compound or when two or more of its elements are open compounds or hyphenated compounds. If two words express a relationship, then an en dash is used. (Note that I’m not able to use an en dash in this Web software, so I’ve tried to size the hyphens in this list so that they look more like en dashes.)
post-World War II years (one of the elements, World War II, is an open compound)
parent-teacher conference (expresses relationship)
coach-athlete communication (exresses relationship)
true-false questions (coequal compound)