Hyphen: A Simple Guide to Rules and Usage

When To Use a Hyphen

You can find the hyphen symbol (-) on your keyboard, typically at the end of your number row near the zero (0) key. There are several occasions when you need to use a hyphen to be grammatically correct.

How To Use Hyphens in Compound Words

Combining two words makes a completely different word known as a compound word. Most compound words don’t need a hyphen, but in some cases, they do. For example:

You may see these rules in sentences like:

• The two-hour class is almost over.
• It’s a good idea to avoid lead-based paints if possible.
• Recess became a free-for-all once it started raining.
• This article about healthy eating is a real eye-opener.

How To Use Hyphens With Prefixes and Suffixes

Most of the time, adding affixes to a word doesn’t require a hyphen. In some cases, however, it’s a good idea to hyphenate the prefix or suffix to its base word, including: 

Examples of these hyphen rules in a sentence include:

• Bullying can negatively affect teenagers’ self-esteem. (Hyphenate self-)
• My children believe I am all-knowing. (Hyphenate all-)
• Do you know my ex-husband? (Hyphenate ex-)
• Let’s conduct a meta-analysis of the research. (Hyphenate when prefix and word share a letter)
• That is a beautiful pre-Raphaelite painting. (Hyphenate when prefix comes before a proper noun or adjective)
• There will be thirty-odd kids at the party. (Hyphenate suffix -odd)
• I love these restaurant-style tortilla chips. (Hyphenate suffix when noun has three or more syllables)
• The pitcher has a drip-proof lid. (Hyphenate when suffix and word share a letter)

Other Times To Use a Hyphen

You’ll want to use a hyphen in a few additional situations. Compound numbers (numbers 21-99) and fractions always require hyphens when written out. It’s also a good idea to include a hyphen when the unhyphenated version of the word is a completely different word (such as prefix, as in “a word placed in front of another” and pre-fix, as in “before a fix”). For example:

Examples of these hyphen rules in sentences include:

• The car was going fifty-five miles per hour. (Hyphenate compound numbers)
• Sheryl bought twenty-eight pencil boxes. (Hyphenate compound numbers)
• One-third of freshmen stayed in the dorms. (Hyphenate fractions)
• The kids ate three-quarters of the pizza. (Hyphenate fractions)
• I re-sent the letter. (Not resent)
• Most of the fans in the stadium are pro-State. (Not prostate)

When Not To Use a Hyphen

It seems like using a hyphen is often the safe choice in writing. Generally, that’s true — although there are a few times when you shouldn’t use hyphens. These occasions include:

• when a compound adjective follows the noun (“the well-known artist” vs. “the artist is well known”
• when an adverb ending in -ly modifies a noun (“the happily singing children”)
• when using most prefixes or adjectives (countrywide, nondairy, untouched)
• in closed compound words (lighthouse, firefighter, keyboard)

When To Use a Dash Instead of a Hyphen

Many people confuse hyphens and dashes because they look similar in printing. However, they serve very different purposes.

• Hyphens (-) connect words and parts of words, and aren’t separated by spaces.
• Dashes, (–) and (—), indicate ranges or pauses in writing, and are usually separated by spaces.

The common rule of thumb is to use a dash when showing a break in the text, a range in dates or time. Use a hyphen to create a connection between two words.