Hyphens (-)

Hyphens are only used to combine certain words together. They are not strong enough to set off phrases or words from a sentence. Use hyphens in the following situations:

• Use in compound numbers and fractions.

Examples: twenty-nine, two-thirds

• Join multi-word nouns read as a single unit.

Examples: sister-in-law, nine-year-old, mid-July

• Combine two adjectives that are working together to describe the same noun.

Example: Maria is a self-conscious writer.

Maria is not a self writer or a conscious writer: both words must work together to describe her, so they are hyphenated.

• Combine a complete phrase before a noun. These hyphens are no longer needed when the phrase comes after the noun.
  • 26-year-old woman     but    woman who is 26 years old
  • 10-page paper     but    a paper that is 10 pages long
  • new-consultant training     but     training for new consultants
  • over-the-counter medicine     but     medicine that is over the counter
• Don't use between an adverb and adjective.

Example: They shared a very tender and extremely memorable moment.

• Always use between an adverb and a participle (verb form that describes a noun). Consider the following examples:

Examples: well-developed, well-known, self-correcting, home-cooked, problem-solving, ill-advised, fast-moving, friendly-sounding

• Use a "suspended" hyphen when at least two similar compound words appear next to each other and the final portion of the compound has been eliminated to avoid repetition. The hyphen appears after the first compound, regardless if the compound normally has a hyphen. A hyphen occurs in the main compound only if it would normally be hyphenated. 

Example: Are her father- and mother-in-law coming over for dinner?

Example: Is it a nine- or ten-story building?

Example: He under- or overestimated all of his opponents.

Example: Mrs. Harris has taught first-, second-, and third-grade at my elementary school.

Proofreading Tip

If you're unsure whether a hyphen is needed, check an online dictionary or paste the phrase into Google and check common usage.

Short Dashes

Short dashes ( – ) are more commonly called "en" dashes, because they are the length of the letter "n" and often combine numbers. Short dashes often replace hyphens to prevent confusion and have the following roles:

• Substitute the word "through" in a range of inclusive numbers or months. See these examples:
  
  • January–April (meaning January through April)
  • one–five (meaning one through five)

• Take the place of a hyphen when one part of a compound word is hyphenated or made of two separate words. Consider these examples:
  
  • anti–New York view
  • New Jersey–Paris flight
  • non–computer literate adult
  • pro-life–pro-choice debate

Long Dashes (—)

Long dashes (—) are more commonly called "em" dashes, because they are the length of the letter "m." These longer dashes are created in Microsoft Word by placing two hyphens right after a word and hitting Enter. Word will then autocorrect the two hyphens into a dash. Use long dashes in the following situations:

• Emphasize additional information in the middle or end of a sentence. Long dashes provide more emphasis than a comma or parentheses and can indicate a pause to slow your reader.

Example: Daniel—in all fairness—had no choice but to become Mrs. Doubtfire.

Example: She was an ESL (English as a second language) student—someone who is still learning how to speak/write in English.

• Replace commas to prevent confusion when restating or describing a noun.

Example: The Spice Girls—Sporty, Baby, Posh, Scary, and Ginger—were the biggest cultural icons of the 1990s.

Example: When I woke up, I had a lot of cold symptoms—coughing, sneezing, and a headache.

• Indicate an abrupt change in thought or shift in tone.

Example: Jurassic World was amazing with today’s graphics—but I’m getting ahead of myself.

• Replace a semicolon to combine two complete sentences.

Example: The Eiffel Tower is the most visited paid monument in the world—it features restaurants on both the first- and second levels.

Long dashes can either have spaces on both sides or no spaces on either side.

Example, with spaces: Dinner tonight is going to be so delicious — roast beef, green beans, and potatoes!

Example, without spaces: Dinner tonight is going to be so delicious—roast beef, green beans, and potatoes!

---