Knowing when to use a hyphen can be confusing, given that several rules are governing the utilization of this mark. The most common errors we see is in the case of hyphens between compound adjectives. Compound adjectives are two words that work together to create a single modifier before a noun.

Let’s look at an example sentence: The three-legged dogs were hungry. In this sentence, “three-legged” is a compound adjective modifying “dogs.” Without the hyphen, the sentence is still understandable, but the intended meaning is lost: The three legged dogs were hungry. In this case, your reader may misunderstand that three dogs with legs are hungry, when in fact you are trying to say that the dogs with three legs are hungry.

Hyphens Between Compound Adjectives

Let’s look at another example. This one also shows the importance of using a hyphen when writing out numbers: Twenty two year olds were drinking beer. What’s wrong with this sentence? Are two-year-olds really drinking beer or are twenty-two-year-olds drinking beer? When writing out two-word numbers, a hyphen should always be used, whether the number is being used as an adjective or not. This sentence is a good example why. I’ve now shown you two examples where a hyphen can completely change the meaning of a sentence.

Let’s look at another example. In this case, the hyphen adds little: The death-defying pilot landed the plane with ease. In this case, it is not likely that a reader would confuse the meaning of the sentence. So is a hyphen necessary here? The answer to this question is a matter of personal choice or an issue of style-guide adherence. Personally, I would recommend using a hyphen here at all times; if nothing else, it adds a level of consistency to your writing.

As a general rule, remember that your goal is to create content that is easily readable. The use of hyphens with compound adjectives will surely improve the readability of your writing.

Summary: Hyphens help to improve the readability of your writing. A common error is to forget to use hyphens between compound adjectives.

Originally posted 5/20/2015 and happily updated 10/26/2017. Thanks for reading!