Updated April 2023

Learning how to correctly use a hyphen is tricky. The function of the hyphen is to clarify, but it sometimes does the opposite, particularly when it’s used with compound adjectives. Here are some basic hyphenation rules to help you decide when a hyphen is necessary and when its use will just muddle your writing—and confuse your reader.

Be sure you know the difference between a hyphen and an en dash.

Rule 1: When compound adjectives come before a noun, the adjectives should be hyphenated.

Compound Adjective: two or more adjectives that work together to describe the same noun

Example 1: On Monday, Mrs. Thomas taught problem-solving skills to her class.

The compound adjective problem-solving tells what kind of skills Mrs. Thomas taught. Since these adjectives come before the noun and work together to describe the noun, it’s necessary to place a hyphen between them.

To understand why the hyphen is needed, remove it, then check the sentence’s meaning—it will be very different:

Example 2: On Monday, Mrs. Thomas taught problem solving skills to her class.

With no hyphen between the two adjectives, the writer’s meaning is unclear. Did Mrs. Thomas teach solving skills that were a problem? Did she teach two types of skills to her class: problem skills and solving skills? Be sure that your punctuation reflects what you’re trying to say.

Also, watch for words that look like compound adjectives but are really separate, independent adjectives. Take a look at the following sentence:

Example 3: Stephen King is a successful, popular writer.

Here, successful and popular do not form a compound adjective; instead, they are two separate, independent adjectives describing writer, and a comma—rather than a hyphen—should be placed between them. Either word could be used by itself, and the sentence would make sense.

Rule 2: If the compound adjective comes after the noun it describes, no hyphen is needed.

Example 4: On Monday, Mrs. Thomas taught her class many skills, including problem solving.

Since problem solving follows the noun (skills), no hyphen is needed.

Sometimes writers may use what is called a suspending hyphen, a hyphen that is used when two or more adjectives have the same base element, and the base element is shown only with the last term. Consider the following examples:

Example 5: Although they couldn’t wait for their new furniture, Bill and Abby knew that there would be a three- to four-day delay in delivery.

Here, three and four share the base word day. The writer could have written three-day and four-day delay, but using the suspending hyphen creates writing that is more succinct and easier to read.

Example 6: Peter’s knowledge of the case was through second- and thirdhand information.

In this sentence, the hyphen after second tells the reader that second shares the same base element as thirdhand, which is, of course, hand. Again, using the suspending hyphen is more efficient than writing secondhand and thirdhand information.

So far, so good, right? Well, there is an exception to these basic hyphenation rules.

Rule 3: Do not hyphenate when the first of the two words ends in -ly.

Example 7: Maddie is an extremely overworked mother.

Extremely is an adverb. By definition, adverbs describe verbs, adjectives, and other adverbs. In this sentence, extremely is not describing mother (which is a noun) but is telling how overworked Maddie is. Therefore, no hyphen is needed between extremely and overworked.

Rule 4: Watch for special hyphenated nouns.

Example 8: She was the runner-up in the beauty contest.

Other examples can include mother-in-law (and the other in-laws), best-seller, follow-up, etc. When in doubt about a hyphenated noun (as opposed to a compound word, such as letterhead or freeway), don’t guess. It’s always best to look it up in Merriam-Webster’s Dictionary (our dictionary of choice).

Hyphens may be disappearing in some cases (thanks to the Internet), but if you proofread your work carefully and follow these basic rules, they won’t trip you up! Learn more about Writer’s Relief expert proofreaders!