Hyphens join related words together in a sentence, such as in father-in-law, five-year-old and sugar-free. They prevent misunderstandings and clarify writing. But when should you use a hyphen — and is a hyphen the same thing as a dash? Find out when a hyphen is necessary, when it’s optional, and when you don’t need one at all.
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:
Use a Hyphen |
Hyphen Examples |
when compound adjectives come before nouns |
grass-fed beef |
with compound words that aren’t combined |
editor-in-chief |
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:
Use a Hyphen |
Hyphen Examples |
prefixes self-, all-, and ex- |
self-esteem |
prefixes and a noun that share a letter |
re-energize |
prefixes before proper nouns or adjectives |
un-American |
suffixes -elect and -odd |
mayor-elect |
suffixes with three-syllable nouns (or more) |
adobe-like |
when a noun and a suffix share a letter |
Moab-bound |
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:
Use a Hyphen |
Hyphen Examples |
with compound numbers (21-99) |
forty-seven |
with fractions (except one half) |
two-thirds |
to avoid confusion |
re-pair (to pair again, not “repair”) |
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.