by Scott Laughlin
HeyTutor Blog Editor

What is a Hyphen?

A hyphen is a short horizontal line (-) that glues words or parts of words together. A fun example would be the name of Marvel’s iconic web-slinging hero—which is “Spider-man” and not “Spiderman.” While a hyphen might look slightly similar to a dash, both are not interchangeable. Hyphens serve a completely different role, as you’ll soon find out. We write hyphens with the symbol (-). If you’re using a U.S keyboard, you’ll find the hyphen symbol next to the “0” key. Understanding when to use a hyphen is easy. You just need to follow a few simple rules.


Using a Hyphen with Compound words (Hyphenated Compound)

We use hyphens when two or more words combine to create a compound word with a new meaning. For instance, the words “broad” and “minded” mean two different things on their own. However, when you pair them together, they form “broad-minded”—which is a compound word with a completely new meaning. Some other examples of compound words that we can create using hyphens include:

  • Two-tone

  • Mother-in-Law

  • Half-baked

  • Sugar-free

  • Get-together

  • Self-restraint

  • All-to-common

  • Good-bye (also spelled goodbye)Using Hyphens with Numbers

Hyphens work with numbers. We use hyphens when spelling numbers between 21 and 99. For instance, if you write out a list of numbers between eighteen and twenty-eight, it should read:

  • Eighteen

  • Nineteen

  • Twenty

  • Twenty-one

  • Twenty-two

  • Twenty-three

  • Twenty-four

  • Twenty-five

  • Twenty-six

  • Twenty-seven

  • Twenty-eight

Hyphens with Fractions

Hyphens also come in handy when we write fractions. The figure is spelled by placing a hyphen between the numerator and denominator. Some examples of this include:

  • One-third

  • Four-fifth

  • Four-tenths

  • Six-hundredth 

Hyphens with Numbers and an Adjectival Compound

Hyphens help join a number with a word when it occurs as a compound adjective. To see how this might work, consider the following examples:

  • John was so exhausted that he slept all through his 10-hour flight. 

  • We have a three-year-old son

  • The last thing he expected to find on his doorstep was a seven-month-old pup

In these examples, 10-hour and seven-month are linked by a hyphen because they are compound adjectives made up of multiple words. We also sometimes use hyphens to connect words with unit abbreviations. For instance:

  • Sarah watered the garden using a 6-ft long hose 

  • Adam struggled to walk up the stairs with the 10-lb bag of flour

Note: Hyphens should never be used with a metric symbol such as ° (degrees).

Using Hyphens with Compound Modifiers

When multiple words join to modify a noun, they become a compound adjective and require a connecting hyphen. Some examples of two-word compound adjectives linked by hyphens include:

  • Will Smith is a well-known actor

  • Cameron is a part-time worker 

  • Kindness is a two-way street

An important rule to remember is that hyphens only connect word-pairs that modify (or come before) the noun.* When the words occur after the noun, they do not always need a hyphen. For instance, we can rewrite the example above as:

  • Will Smith is an actor who is well known

*There are the occasional exceptions. Some editors advise against the use of hyphens with popular compound expressions. For instance, the words high school and ice cream are easy to identify. Still, it’s best to use a hyphen to reduce the risk of ambiguity in a sentence. 

Hyphens with Three or More words

Most compound adjectives consist of two words. However, they can sometimes be longer. For example: 

  • He fell in love with her salt-and-pepper hair

  • Forgetting to use a hyphen is an all-to-common mistake

  • Jane is a far-too-chatty counselor

  • Mark turned out to be a by-the-numbers accountant 


Hyphens with Prefixes and Suffixes

While hyphens are sometimes used with prefixes and suffixes, knowing when to add them can be a little challenging at first. However, you can quickly solve this by following a few quick rules:

  1. Always use a hyphen when the letter at the start of the base word is the same as the letter at the end of the prefix. For example: 

  • Co-occupants

  • Anti-inflammatory

  • Intra-arterial

  1. Use a hyphen with word pairs that start with any of these prefixes:

  • Self (e.g., Self-service)

  • All (e.g., All-knowing)

  • Ex (e.g., Ex-girlfriend)

  1. Use a hyphen whenever a proper noun follows a prefix. For example:

  • Mid-July

  • Pro-Nazi

  • Afro-American

  • Un-British

Hyphens with Suffixes

We use a hyphen with words that end with suffixes like “elect,” “type,” and “designate.” For example, governor-elect, president-elect, and bold-type. Other suffixes that may require a suffix include words that end with like and fold, such as bell-like or twenty-fold.

What is a Suspended Hyphen?

A suspended hyphen (also known as suspensive hyphenation) is an English rule that determines how hyphens work when writing a sentence with multiple hyphenated adjectives that end with the same last word. Instead of listing out all the compound adjectives, we simply add a hyphen to the last word and delete all the other instances. Some examples include:

  • Wrong: “We’re considering a three-week to five-week vacation.”

  • Correct: “We’re considering taking a three- to five-week vacation.”


  • Wrong: “The company is reviewing its open-door and close-door policies.”

  • Correct: “The company is reviewing its open- and close-door policies.”


What’s the difference between a hyphen and a dash?

Although hyphens and dashes are both straight lines, they serve different purposes. A dash (—) is longer than a hyphen (-). Dashes also separate a group of words, while hyphens join words or parts of a word. In some cases, dashes may serve as a replacement for commas or parenthesis. For example:

  • One of the things I love about long-eared dogs—in addition to how adorable they look—is that they’re incredibly loyal.

In the above example, a hyphen is used with long-eared.  In contrast, an em-dash separates the phrase “in addition to how cuddly they are.”


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