Co-worker vs. Coworker
Publishing can’t get its act together on whether to hyphenate co-worker. But there does seem to be a trend toward no hyphen and it couldn’t be uglier to me.
Here’s what AP says:
GUESS Sneaker Fabric Men's Webber Grey co- Retain the hyphen when forming nouns, adjectives and verbs that indicate occupation or status: co-author, co-chairman, co-defendant, co-host, co-owner, co-partner, co-pilot, co-respondent (in a divorce suit), co-signer, co-sponsor, co-star, co-worker.
Use no hyphen in other combinations: coed, coeducation, coequal, coexist, coexistence, cooperate, cooperative, coordinate, coordination.
Elsewhere in the guide, AP encourages hyphenation of compounds that create double vowels, like re-enter. So under co-, AP notes that coordinate and cooperate are exceptions. I assume that’s because they’ve become standard words in English and are no longer considered compounds as much as they are freestanding words.
The Chicago Manual of Style, in its 15th edition, left a lot of wiggle room in their rules, basically allowing users to choose between coworker and co-worker. But its 16th edition takes a firmer stance.
Compounds formed with prefixes are normally closed, whether they are nouns, verbs, adjectives, or adverbs.
Chicago of course makes some exceptions. Most notable is that you should use a hyphen to separate “combinations of letters or syllables that might cause a misreading.” One of the examples they give is “pro-life.”
Yet under the entry for the prefix co-, Chicago actually includes GUESS Men's Webber Fabric Sneaker Grey coworker as an example of a word that does not take a hyphen.
Personally, I don’t see why prolife would be any more troublesome than coworker. In the latter, you’re actually spelling the word “cow” with your first syllable, whereas pro plus L doesn't make a separate word.
I don’t normally argue with style guides’ rules. As far as I’m concerned, they’re just referees making calls – many of them just for consistency’s sake. And I don’t consider style issues particularly important – after all, if serial commas were so important, everyone would have agreed on their utility long ago. Yet serial commas are optional, so I’m fine with letting style guides tell me whether or not to use them.
But coworker is different. It’s ugly, weird and, well, cow-like. Me, I’ll use Webber Fabric Grey Men's Sneaker GUESS co-worker every time I have an option, which, if you know how to read between the lines of a style guide, is pretty often.