Have you ever wondered whether to put a hyphen after a prefix that ends with a vowel, when the same vowel follows the prefix? For example, do you wonder which choices are correct in the title of this blog post?
The question came up today as I was teaching an online Business Writing Tune-Up for employees at a large manufacturing company. One of the employees, Jeff, questioned whether my rendering of reevaluate should have been re-evaluate.
Jeff cited The Associated Press Stylebook (AP), and he graciously even provided the rule from AP:
"Except for cooperate and coordinate, use a hyphen if the prefix ends in a vowel and the word that follows begins with the same vowel."
So Jeff's correction was appropriate, and I would have been wrong–if I were following AP style.
You see, there are often two or more ways of doing things. AP style is just one way. Granted, AP style is a good one to follow, especially in a large company, because it is consistent. Following AP style, you do not even have to think about the words listed below. They are all correct.
According to AP style:
Other reference manuals, including dictionaries, pick and choose which words to hyphenate when the prefix ends with the same vowel that begins the main word. For example, notice the difference in The Chicago Manual of Style renderings.
According to Chicago:
co-opt (like AP)
Chicago does not list co-owner, de-emphasize, de-escalate, or pre-engineered. However, Chicago recommends checking Merriam-Webster's Collegiate Dictionary for words it doesn't list, and Webster's shows de-emphasize, de-escalate, and pre-engineered.
Co-owner doesn't appear in Webster's or in The American Heritage College Dictionary, but it appears in Canadian Oxford Dictionary, which is good enough for me. And hyphenating co-owner follows Chicago's rule of separating "combinations of letters . . . that might cause misreading." The rendering coowner might leave readers guessing a moment too long.
What do you think: Is it re-elect or reelect? Pre-existing or preexisting? If you follow the The Associated Press Stylebook, your answer is clear. Otherwise, like me, you may need to check several resources before you have a definitive answer. My answer to Jeff's question is "I prefer reevaluate." He and I are both correct.
I welcome your comments.