After thumbing through the dictionary or perusing a usage guide, you’d think that the trend in American English and, to a lesser extent, in British English is to omit hyphens from words consisting of a prefix attached to the root word. But reality begs to differ.
Mail sent from nonprofit organizations invariably features the word non-profit in the upper right-hand corner, where a stamp would normally be placed. (By contrast, the US Postal Service, on its Web site, correctly styles the term nonprofit — but the Internal Revenue Service employs the hyphen, as do many such organizations.) Commercial Web sites and product catalogs invite customers to plan ahead, using the word pre-order, though the dictionary listing is preorder. And many print or online references to peace movements feature the term anti-war, despite the designation of the standard form in virtually all writing resources as antiwar.
So, why do descriptivist and prescriptivist handbooks alike exhort readers to close the gap, when so many people who use the English language to communicate in writing ignore or are ignorant of the authorities’ citations?
The natural trend in associating words or parts of words is to first combine them in open compounds, later hyphenate them as they become more established, and finally convert them into closed compounds when familiarity is thoroughly achieved (though many compounds remain open or hyphenated long after these evolutionary stages seem overdue). But most writers — seemingly a majority of amateurs and definitely too many professionals — don’t pay attention to such details, though the standard is easily ascertained by a glance in a dictionary or another resource.
The exceptions to the preponderance of closed prefixes are relatively few and more or less simple. Retain a hyphen in the following cases:
- When the root word is a proper noun (post-Depression) or a number (pre-1914)
- When the prefix precedes an existing prefix (non-self-governing)
- When the prefix precedes a proper open compound (“pre-Civil War”) — in such a case, the symbol should technically be an en dash, to help clarify that pre- modifies “Civil War,” not just the word it is actually attached to, but many publications, print and online, use a simple hyphen
- When two instances of the letter i or the letter a are adjacent (anti-intellectual, extra-action), or another combination of letters could hamper reading (pro-labor and many other pro- constructions)
- When a prefix is repeated (anti-antibody)
- When suspensive hyphenation is employed (“over- and understimulation”)
Also, some people find it awkward to close up co- and a word starting with c (they prefer co-chair to cochair), with o (co-owner is preferred to coowner), or even with any word (coworker, instead of co-worker, annoys many writers).
In addition, there are isolated illogical exceptions. For example, why close up reentry but hyphenate de-emphasis? And an otherwise superfluous hyphen is often inserted to distinguish homographs (as with re-count, “to tally again,” as opposed to recount, “to narrate”). Some writers ignore this seemingly overcautious strategy, though a clear context doesn’t necessarily obviate it. (Sometimes, the distinction does seem unnecessary: How many people write recreate as the verb form of recreation compared to using the prevalent usage, meaning “to create again”? But, oddly, the dominant homograph is given the hyphenated form.)
Despite this apparent multitude of deviations from the norm, there is a norm: An overwhelming majority of prefixes are closed. But if you’re ever in doubt, just consult your dictionary.