How Do You Use a Hyphen?

hyphen, typewriter

The hyphen, along with its cousins the en and em dash, may be the most misunderstood punctuation mark in English. Hyphens are used to join parts of a word or compound phrase, as in ex-wife, full-length mirror, and by-the-book negotiations. As the Chicago Manual of Style puts it, “Far and away the most common spelling questions for writers and editors concern compound terms—whether to spell as two words, hyphenate, or close up as a single word.”

One reason that hyphenation is so complex: it changes over time. A tour through the Google nGram view of many common words reveals their hyphenated predecessors: co-operate became cooperate, to morrow became to-morrow and then tomorrow, and good-bye became goodbye (though both are still acceptable). Some modern terms, like website/web site, have recently settled their usage wars, but email/e-mail is still anyone’s guess. Email may be slowly winning that battle, though uses of e-book outnumber the closed ebook and eBook. A dictionary definition is often the best place to go to seek clarification, or at least understand your options.

Another reason hyphenation can be confounding is that the best practices of usage leave room for interpretation. The main function of hyphens in compound modifiers, or groups of words working together to modify a noun, is to eliminate ambiguity of meaning. For example, in the phrase “up-to-date technology,” we hyphenate “up-to-date” to signal that these three words are to be read as one concept, or adjective, functioning to modify the word “technology.” This way, nobody will make the mistake of reading this phrase as an expression of readiness to go on a romantic date with technology, or as a readiness to mark technology with the day, month and year. In another example, a “heavy-metal detector” detects heavy metals (or perhaps heavy-metal music), but a “heavy metal detector” is a metal detector that is heavy. However, ambiguity can be a subjective matter; as the Chicago Manual states: “Where no ambiguity could result…hyphenation is not needed.”


Age terms are another stumbling point for many. The hyphenation in the following two examples is appropriate: I have to babysit my three-year-old cousin; he has a five-year-old. However, in the following sentence in which the age comes after (rather than before) the noun it modifies, no hyphenation is needed: Sheila is seven years old. One trick of the trade is to look for the plural of “years” in such constructions. If the word “years” is plural, chances are the construction does not need hyphenation.

Compound modifiers in which the adverb ends in -ly do not take a hyphen, as in overly thorough exam. In addition to numerous sections devoted to hyphens, the Chicago Manual also offers a 10-page hyphenation table, which any good copy editor finds indispensable.

What problems do you have with hyphens? Do you have any hyphen questions you’d like to see addressed on the Dictionary.com blog?

Love learning about punctuation? What’s the difference between the colon and the semicolon?


  1. CARLEY REINERT -  August 24, 2016 - 4:43 pm

    Savvy comments – I was enlightened by the specifics ! Does someone know where I can access a sample a form document to complete ?

  2. Nadome dominic -  June 27, 2016 - 3:03 am

    Great site.Truly helpful.

  3. jonathan -  February 5, 2015 - 1:01 am

    I really enjoy the photo for this article. =^)

    • Ricardo -  February 15, 2016 - 6:50 pm

      What is the or a correct way to hyphenate the adjectives in this string of words: the late great American Mezzo-Soprano Regina Resnik?

  4. QiPo -  July 24, 2014 - 4:11 pm

    Obstructionist: My, oh my folks. What bee got into your bonnet over this one word. Your political slip is showing. The distortion of language is a an age old technique of controlling its use. It is commonly used in politics and has proven to be a valuable propaganda tool by many governments. The interesting fact is, I personally know people on the left, right, and center that are obstructionists. It is not limited to any particular kind of person, whether male, female, or undecided. It is not limited to any particular political body either. It reflects the behavior of an individual. Any race. Any creed. Any sex. To use it as a pejorative in order to make a political point is absolutely obstructionist as it tries to silence dissent. Therefore, your blog site is a bald faced obstructionist site for it impugns only one segment of the political life in America. The segment you chose to disparage. Congratulations on both your obstructionism and prejudice.

    • What on earth? -  February 15, 2015 - 2:20 am


    • melisme -  February 21, 2015 - 9:51 am

      Learn to spell. What the Hell does all that crap you wrote have to do with hyphens??? Absolutely nothing! Go away.

    • Kit Snicket -  March 9, 2015 - 8:22 pm

      It might just be me, but I believe this man, woman, or beast of indeterminate species is what is commonly referred to as a troll. All for burning his house down, say “V.F.D.”

  5. Driftboy -  June 4, 2014 - 6:56 am

    Haaaaaa! B-) as on eof today’s rap artists I feel we should be allowed yo use hyphens whenever we please ;-) because we as the youth of today speak in “SLANG” and “TWANG” , so it becomes quiete a challenge for us to change the ways in which we use certain symbols :-( ….but moving forward, let us make use of them in te right manner so out following generation will learn from their seniors B-) :-D :-)

    Twitter: @Real_Driftboy :-D

    • Pave' Stiletto -  September 12, 2014 - 7:34 pm

      Are you retarded or what? When cRap has gone the way of the dinosaurs, it will have been considered a moment in time in which America tried to decide if it was a pile or garbage.

    • Janie -  February 14, 2015 - 9:18 am


      • Kit Snicket -  March 9, 2015 - 8:23 pm

        ‘Facedesk’ is far more refined, my dear.

        • connor -  January 17, 2016 - 6:32 pm

          yes, ‘Facedesk’ is far more refined

  6. NixonSpade -  April 10, 2014 - 1:31 pm

    Ohaiyo! I need to look up some more words like these, the competition between hyphen or non-hyphened seem interesting!

    That’s all.

    • helen -  July 31, 2014 - 2:31 am

      Ya dat is true bt y is hyphen important

  7. Greg -  April 9, 2014 - 7:56 pm

    I teach the following hyphen rules in my high school English classes:

    1. Use between syllables of a word to begin the word at the end of a line and continue it on the next.

    2. Use it when spelling the numbers twenty-one through ninety-nine (excluding multiples of ten, obviously).

    3. Use it for the the prefixes self-, ex-, great-, and all- (acronym SEGA for easier remembering).

    4. Use it for compound adjectives that precede the noun they describe. (For example, he is a world-champion fighter, and the fighter is a world champion.)

    5. Use it to prevent confusion between two different words with otherwise identical spellings (e.g. recreation and re-creation).

    6. Use it to separate two consecutive vowels that are not part of the same syllable (e.g. re-emerge, co-owners, and anti-irritant).

    • RIz -  April 10, 2014 - 9:01 am

      Thank you! Do you have an example of #1? :)

      • Elmer -  April 10, 2014 - 12:34 pm

        To use between syl-
        lables of a word to be-
        gin the word at the end
        of a line and contin-
        ue it on the next.

    • Robert L -  February 6, 2015 - 6:37 am

      Thanks for the little mnemonic device SEGA. Image, “I’ll give you twenty-one hundred dollar bills” versus, “I’ll give you twenty one hundred dollar bills”. A difference of $100 to be sure if one doesn’t use either the hyphen or the dollar sign.

    • ROSHY KEEPER -  October 12, 2016 - 12:01 pm


  8. TDawg -  April 9, 2014 - 7:44 pm

    I’m ‘only’ 50 and I never got the memo on good-bye/goodbye. I much prefer the old way.

  9. Q -  April 9, 2014 - 2:08 pm

    I would love to learn more about when to use the em dash. I am pretty sure I overuse them in both formal writing and informal writing. When is the appropriate occasion?

    • Adina -  August 4, 2014 - 4:07 pm

      The occasionally annual em-dash free-for-all celebration, of course!

  10. anonymous -  April 9, 2014 - 1:23 pm

    Well, I won’t be reading the manual (start in Chicago and drive north until the arctic ocean and you’ll understand), but I get the point conveyed. It reminds me slightly of a tumblr chat I saw that went something like this:
    English is so confusing, since read rhymes with lead and read rhymes with lead but read doesn’t rhyme with lead and read doesn’t rhyme with lead.
    Generally, I only use hyphens in numbers, tmeses, and the places that seem right, but not much in words.

  11. Mike -  April 9, 2014 - 3:18 am

    Although both are used, co-operate with a hyphen is still preferred in UK English and most English-speaking countries outside the US. Strangely, uncooperative seems to have dispensed with it.

  12. OED -  April 8, 2014 - 11:56 pm

    There is a term that refers to the elision of a word that was previously hyphenated. That word escapes me now, but it’s odd that it wasn’t used in this article.

    • Jesse -  April 10, 2014 - 2:34 pm

      The “term” that you wrote about, OED, is portmanteau.

      • Adina -  August 4, 2014 - 4:08 pm

        “Portmanteau,” is, of course, the combination of “portman’s toe.”

  13. Ketselyn -  April 8, 2014 - 8:56 pm

    I’ve always written “web site” as two words, as it can be rewritten as “a site on the web”. Not the best example, but it leads into something else you see a lot of today: web sites, games, and other on-line applications spelling “log in” and “log out” as single words. I mean, you wouldn’t say “I logoutted of the game.” You’d say “I logged out of the game.” :)

    • Helen -  April 10, 2014 - 1:31 pm

      Regarding log in vs. login. When used as a verb, it’s two words, e.g., “I log in to the website.” If it’s a noun, it’s one word, e.g., “I forgot my login.”

    • unicorn666 -  May 2, 2014 - 11:04 am

      -.- same here… I also used “website” as to words too… :3 :D

      • unicorn666 -  May 2, 2014 - 11:05 am

        Log in vs coming here… ugh why do I always get logged out here… DX

    • unicorn666 -  May 2, 2014 - 11:08 am

      I also used to call “blueberry” to words also I called it “blue-berry or blue berry”

  14. Shalini V -  April 8, 2014 - 8:27 pm

    A very good start of the day with such wonderful information about hyphen, n dash and m dash..:)

  15. Kyle -  April 8, 2014 - 6:00 pm

    You say you don’t need to hyphenate an age when it’s after the noun it modifies. But then you say it’s when the word “years” is plural. So suppose your example “Sheila is seven years old” were instead “Sheila is a seven-year-old”? Wouldn’t you need to hyphenate it then? Doesn’t that make your statement about the age being after the noun misleading and wrong?

    • Elmer -  April 10, 2014 - 12:29 pm

      When you say “Sheila is a seven-year-old,” the noun being modified is not “Sheila.” Rather, the noun being modified is unsaid but understood.

      What you are actually saying is “Sheila is a seven-year-old child.”

      Unless, of course, Sheila were a dog — in which case the noun being modified was mis-understood.

  16. nicholas onan -  April 8, 2014 - 11:30 am

    Great f—-n’ stuff~

  17. yo ppl -  April 8, 2014 - 10:42 am

    I think that’s very interesting, I use goodbye, but I had no idea how many people say good-bye! And how goodbye has gotten more popular over the years, WOW! I love this website!!!!

    • Elmer -  April 10, 2014 - 12:38 pm

      You probably have no idea how many people say “good-bye” because they don’t say “good hyphen bye.”

      ‘Goodbye” and “Good-bye” both sound the same when you say them.

  18. Ahmad McDaniel -  April 8, 2014 - 7:17 am

    Great site.

  19. B Pat -  April 8, 2014 - 6:13 am

    Great blog post, I really enjoyed reading. But, like Tyler L, (or is it: like – Tyler L -?) I am intrigued about the usage of the em dash.

    X states some examples of the em dash as follows:

    You are the friend—the only friend—who offered to help me.

    Never have I met such a lovely person—before you.

    I pay the bills—she has all the fun.

    A semicolon would be used here in formal writing.

    If I were to write these sentences myself I would most likely use commas or semi-colons (semicolons?) in their place. I gather that eiter would be grammatically correct? If this is so, how do authors capitalise on the usage of em dashes to add to their writings?

    Kindest regards

    • Elmer -  April 10, 2014 - 12:45 pm

      In my rule-of-thumb for semi-colons, both sides of the semi-colon have both a subject and a predicate; not so with a comma, I believe.

  20. William -  April 7, 2014 - 6:26 pm

    As a graphic designer I am aware that there are three types of “dashes” that are often confused. Indeed, most people are not even aware of these parts of writing.

    As mentioned above, the hyphen conjoins two words (or a prefix/suffix and a word) to form a new word. The hyphen is also used between syllables when a word is broken at the end of a text line. The hyphen should never be confused with a dash.

    Second is the “n dash”. Longer than a hyphen, the n dash connects two equal but separate words (usually nouns) in the same way as an ampersand (&) to indicate a combined identity. The n dash can also be used as an abbreviation in place of “to”, “through”, and other connecting words, e.g., instead of writing 2pm to 4pm, you might write 2–4pm.

    The third dash is called an “m dash” (—) which is the longest (an ‘m’ space as opposed to an ‘n’ space). The m dash is “used to indicate an abrupt change of ideas, but should be used sparingly. It can be used for visual effect in place of commas or parenthesis. The m dash may also be used to indicate a summarizing thought or afterthought at the end of a sentence, or to set off a word or phrase for emphasis.”

  21. Tyler L. -  April 6, 2014 - 8:51 am

    You briefly mention the en and em dashes in the beginning of the blog, and I am wondering how their usage differs, if at all, from the hyphen. I enjoy reading and writing stories, and from what I’ve observed, the em dash usually gets used to insert a separate thought into a sentence in the place of parentheses or a semicolon, or to signify that a person speaking has been abruptly cut off before his/her thought could be completed. As least, this is what I think the usage is; I’m not entirely sure, which is why I’m writing to you. Then there is the en dash, the middle of the three, which I am not really sure how to use at all. I know authors have their own styles of writing, which oftentimes break the rules of grammar, but I’m hoping you could tell me more about what those rules actually are. Thank you for your advice!
    Loyal Scarlet

    • Anat D. -  April 8, 2014 - 6:05 am

      You are correct regarding the em-dash. I think of the en-dash as being used in place of the word “to” in ranges: 1900–1910, 3–5 years old, etc. However, if “from” is used, I prefer “to” over a hyphen, as per Chicago Manual of Style. The en-dash is also used in place of a hyphen when one of the two elements being joined is an open compound: Pre–Civil War era
      Pulitzer Prize–winning, etc.

  22. Jacob -  April 6, 2014 - 4:29 am

    This is very helpful to me.


    • Karon -  April 6, 2014 - 2:15 pm

      While I’m not what you would call a scholar, I’ve been fascinated with words, their meanings and how to use them for most of my 60 years. I truly enjoy this site!

    • yo ppl -  April 8, 2014 - 10:42 am

      Same here


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