Words that often appear together and refer to a single object or concept tend to be combined over time. My favorite example is railroad, which, when railroads were new, was rendered either as rail road or rail-road. Other happily combined words include baseball, horseshoe, homework, and steeplechase.

Such word combinations are not always felicitous, however. Consider words such as fundraise, yearslong, and monthslong. Similarly problematic are words created with prefixes. Consider deskilling, coworker, preeminent, and even cooperation. What is wrong with these closed compounds?

When certain words collide to become closed compounds, they confuse the reader because syllabication is not perspicuous. The first time I encountered deskilling, for instance, I wasn’t sure if it was des-killing or perhaps desk-illing. Only through context was I able to discern that the word was actually de-skilling. Similarly, the digraphs dr in fundraise, and sl in yearslong and monthslong are confusing. Is coworker really cow-orker? Is preeminent preem-inent? Is cooperation actually coop-eration. In most of these compounds, the words are better rendered as hyphenated compounds to avoid confusion: de-skilling, fund-raise—actually, I think raise funds is a better choice and don’t really understand why fundraise¸ however written, should exist—years-long, months-long, and co-worker. Preeminent and cooperation may better be rendered as pre-eminent and co-operation, but they are common enough to be closed compounds. But to deal with the oo and ee digraphs unambiguously, a, diaeresis can indicate that those letter combinations do not represent single sounds: thus, preëminent and coöperation. (Such spellings only seem to occur in The New Yorker.)

One other word deserves special mention. Electronic mail was at first written as e‑mail. Fastidious writer that I am, I still use this form, though I have been accused of being a fussbudget. Anyway, the world at large uses email without apparent embarrassment. This rendering suggests that the word should be pronounced as if it were em-ail, which, of course, makes no sense. Apparently, some people cannot be troubled to find the hyphen on the keyboard. Happily, e-commerce has resisted becoming a closed compound; ecommerce could easily be mispronounced.

— LED, 6/22/2026