If the apostrophe is the most misused punctuation character in the English language, the hyphen must be a close second. Any good authority on grammar and punctuation will have pages and pages of rules for the use of the hyphen. This is not one of them. It’s just a list of the three most common misuses and abuses of the hyphen found on Yahoo!.
Hyphenating a word that doesn’t have a hyphen
The only way to be sure that a word should be hyphenated is to look it up in a dictionary. Nevertheless, many writers fail to take that simple, straightforward step and add a hyphen to a word that is derived from two or more words. Be sure to check out the 30 words that appear most often on Yahoo! with an unnecessary hyphen.
Adding a hyphen to an adverb ending in LY
You don’t need it. Don’t put a hyphen after an adverb ending in LY. Ever. The LY at the end of the adverb is enough to signal to your reader that it modifies the word that follows it.
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Omitting the hyphen in an age or adding a hyphen to an age
It seems to be a contradiction, but sometimes an age requires 2 hyphens and sometimes not. Here’s a simple rule: if the expression contains years old (note that plural years), omit the hyphens. If it contains year old (and that singular year), include two hyphens, before and after the word year.
She’s 35 years old, but she writes like a 10-year-old.