• A hyphen looks like this:

-

• A hyphen is:
• used both to join words and to separate syllables
• often confused with a dash, which is longer
• used as a multiple-word modifier, as in blood-red moon
• used to denote syllabification, as syl-lab-i-fi-ca-tion
• Nouns formed of a noun and an adjective are frequently hyphenated, as death-wish
• Names for numbers from twenty-one to ninety-nine have hyphens
• If a word is split onto two lines, a hyphen will usually be inserted immediately before the split
• The hyphen (‒) is a punctuation mark used to join words and to separate syllables of a single word. The use of hyphens is called hyphenation. The hyphen should not be confused with dashes (‒, –, —, ―), which are longer and have different uses, or with the minus sign (−), which is also longer.
• Hyphens are mostly used to break single words into parts, or to join ordinarily separate words into single words. Spaces should not be placed between a hyphen and either of the words it connects

• Examples where meaning is changed due to the placement of hyphens
• disease-causing poor nutrition meaning poor nutrition that causes disease
• disease causing poor nutrition meaning a disease that causes poor nutrition
• a man-eating shark is a shark that eats humans
• a man eating shark is a man who is eating shark meat
• a blue green sea is a contradiction
• a blue-green sea is a sea whose color is somewhere between blue and green
• three-hundred-year-old trees are trees that are 300 years old.
• three hundred-year-old trees are three trees that are 100 years old.
• Additional examples of proper use
• text-only document or the document is text-only
• Detroit-based organization or the organization is Detroit-based
• board-certified strategy or the strategy is board-certified
• thought-provoking argument or the argument is thought-provoking
• time-sensitive error or the error is time-sensitive
• case-sensitive password or the password is case-sensitive
• light-gathering surface or the surface is light-gathering
• award-winning novel or the novel is award-winning (but, more likely, …won an award with no hyphen)
• web-based encyclopedia or the encyclopedia is web-based
• fun-loving person or the person is fun-loving
• how to wire-transfer funds