Hyphens are the bane of many a great writer’s existence. Mention this simple dash in an online blog writing forum or message board and you are sure to stir up controversy. The best way to make sure you get things “right” is by checking The Chicago Manual of Style, or whatever style guide your project uses as a reference. Unfortunately, this is not always possible. While like most things in the English language there are dozens of exceptions, here are three main reasons you choose to use this particularly persnickety piece of punctuation.
Creating Compound Modifiers
Compound modifiers are simple, hyphenated terms usually placed before a noun and used as an adjective. “A well-known actor,” “the eight-year-old boy,” and “a long-tailed cat” are all examples of compound modifiers. But often the same words used after the noun and verb would not be hyphenated. For example: reverse “a well-known actor” into “the actor is well known,” and the same term is used without a hypen. One world of caution involves the use of adverbs (adjectives ending in “ly”) in creating compound modifiers. In this case, the hyphen is usually left out.
Compound Numbers
When writing numbers between twenty-one and ninety-nine, use a hyphen between the two words. The hyphen is also used in fractions of any size. To give a brief example of both these uses, consider this sentence: On my twenty-first birthday I gave one-fourth of a pizza to twenty-one of my closest friends.
Adding Certain Prefixes
Many prefixes take a hyphen — some of the most common hyphenated prefixes include “self,” “all” and “ex.” As an example: My all-knowing ex-husband makes me lose self-control.
Another place you can nearly always feel confident using a hyphen with prefixes is when the prefix ends with the letter that begins the word you are attaching to it. For example: I de-emphasize the use of the detour on Main Street. De-emphasize was hyphenated while detour was not.
A Final Word
When in doubt—hyphenate. You should always check your style guide or the dictionary, but if you are writing and simply cannot determine whether a word should have a hyphen or not, go ahead and add it. The hyphen as a punctuation mark is a helping hand for the reader. It lets him or her easily determine that the two words go together. If you are that torn on whether or not it is useful, it will probably not hurt your work to include it, and it may make reading easier.
