Ask the Editor: When and how do I use hyphens and dashes?

This is a column by Kira McFadden

[jbox]Melissa Storm asks: This question is about my favorite punctuation mark—the dash. When is it okay to use? When is it overkill? Are there rules for using it as opposed to commas, parentheses, or colons?[/jbox]

Kira answers: To begin, let me first say that the Chicago Manual of Style, either in print or online should be referenced by all authors and editors—it is the best place anyone with literary passion can go to answer any number of questions. Thank you, Coral Russell, for asking.

Pages 331–336 in the Chicago Manual of Style:  Sixteenth Edition state the rules for using different kinds of dashes and hyphens. The Manual of Style explains the differences between the hyphen and four types of dashes.


hphen –            en dash –         em dash —      2-em dash ——           3-em dash ———


The hyphen (-) should be used in compound names and words as follows:

In phrasal adjectives, which follow “three basic rules:  (1) Generally, if it is placed before a noun, you should hyphenate the phrase to avoid misdirecting the reader {dog-eat-dog competition}.There may be a considerable difference between the hyphenated and unhyphenated forms. For example, compare small animal hospital with small-animal hospital. (2) If a compound noun is an element of a phrasal adjective, the entire compound must be hyphenated to clarify the relationship among words {time-clock-punching-employees}. (3) If more than one phrasal adjective modifies a single noun, hyphenation becomes especially important {nineteenth-century song-and-dance numbers} {state-inspected assisted-living facility}” (Style manuals 227).

Please also note that hyphens should be “used to separate numbers that are not inclusive, such as telephone numbers, social security numbers, and ISBNs. It can also be used when spelling out a name or word letter by letter, in dialogue, in American Sign Language, and elsewhere” (Style manuals 331).



1-800-999-3654 or (1-800) 999-3654

“My name is Allison; that’s a-l-l-i-s-o-n.”

The Chicago Manual of Style also notes:  “Hyphens can also appear in URLs and e-mail addresses. A hyphen must not be added to such a string when it breaks at the end of a line (see 2.12, 7.42)” (Style manuals 331).


The en dash (–) is usually used to connect numbers and, less often, words. Continuing numbers (dates, times, and page numbers) use an en dash, which represents up to and including (Style manuals 331–332).


The years 1558–1746 were very troublesome.

Chapters 17–26 show the rise in civilization.

“In Genesis 6:13–21 we find God’s instructions to Noah” (Style manuals 332).

For more examples, see The Chicago Manual of Style:  Sixteenth Edition, section 6.78.


The em dash (—) (sometimes simply called the dash) can function as an alternative to parentheses, commas, or a colon, and is most often “used to set off an amplifying or explanatory element” in a sentence or story—especially when there is an abrupt break in thought (Style manuals 333–334).

For replacing a colon:

“It was a revival of the most potent image in modern democracy—the revolutionary idea” (Style manuals 334).

For replacing parentheses:

“The influence of three impressionists—Monet, Sisley, and Degas—is obvious in her work” (Style manuals 334).

For replacing commas:

“She outlined the strategy—a strategy that would, she hoped, secure peace” (Style manuals 334).

Please note that to avoid confusion, “the em dash should never be used within or immediately following another element set off by an em dash (or pair of em dashes). Use parentheses or commas instead” (Style manuals 334).


“The Whipplesworth conference—which had already been interrupted by three demonstrations (the last bordering on violence)—was adjourned promptly.


The Whipplesworth conference—which had already been interrupted by three demonstrations, the last bordering on violence—was adjourned promptly” (Style manuals 334).

Also note that an “em dash is occasionally used to set off an introductory noun, or a series of nouns, from a pronoun that introduces the main clause” (Style manuals 334).


“Consensus—that was the will-o’-the wisp he doggedly pursued” (Style manuals 334).

Em dashes also indicate sudden breaks in thought, sentence structure, or an interruption in dialogue—however, an em dash should not be used when a person is faltering in speech. Then, it is best to use an ellipsis (“I…I…uh, I’m not sure why the chicken…well, it was just…”) (please also see section 13.39 in The Chicago Manual of Style to learn more) (Style manuals 334).


“‘Will he—can he—obtain the necessary signatures?’ asked Mill” (as opposed to:  “‘Will he…can he…obtain the necessary signatures?’ asked Mill.” In this one, it should be noted the speaker is stuttering, not verifying.) (Style manuals 334).

An em dash may also be used before expressions such as that is or namely. For examples, see section 6.43; see also section 6.56 (Style manuals 335).

This is important to remember:  “In modern usage, if the context calls for an em dash where a comma would ordinarily separate a dependant clause from an independent clause, the comma is omitted. Likewise, if an em dash is used at the end of quoted material to indicate an interruption, the comma can be safely omitted before the words that identify the speaker” (Style manuals 335).


“Because the data had not been fully analyzed—let alone collated—the publication of the report was delayed” (Style manuals 335).

“‘I assure you, we shall never—’ Sylvia began, but Mark cut her short” (Style manuals 335).

Note:  At the end of a quoted sentence where you choose to end with an em dash, the quotations will try to face the wrong way if you use Smart Quotes (“I never—“). To fix this, use another letter at the end (“I never—l”) and delete the letter after the quotes are correctly placed (“I never—”). Also, note that if you ask a question and end it with an em dash (“Why would I ever—”), it is correct to end it with a question mark (“Why would I ever—?”) unless you continue the question on another line (“Why would I ever—” “But mom, I need to get Teddy!” “—run a twenty-mile marathon with a bad leg?” she demanded.).

Note:  Keep in mind that, according to The Chicago Manual of Style:  Sixteenth Edition (Style manuals 335),  “In modern usage, a question mark or an exclamation point—but never a comma, a colon, or a semicolon, and rarely a period (see 14.16)—may precede an em dash.”


“Without further warning—but what could we have done to stop her?—she left the plant, determined to stop the union in its tracks” (Style manuals 335).


The 2-em dash (——) “represents a missing word or part of a word, either omitted to disguise a name, an expletive, or else missing from or illegible in quoted or reprinted material. When a whole word is missing, a space appears on both sides of the dash. When only part of a word is missing, no space appears between the dash and the existing part (or parts) of the word; when the dash represents the end of a word, a space follows it (unless a period or other punctuation immediately follows)” (Style manuals 335–336).

“‘The religion gives its —— to the language spoken there’” (Style manuals 336).

“Admiral N—— and Lady R—— were among the guests” (Style manuals 336).

“David H——h [Hirsch?] voted aye” (Style manuals 336).

The Chicago Manual of Style notes, “Although a 2-em dash sometimes represents material to be supplied, it should not be confused with a blank line to be filled in; a blank form should appear as an underscore (e.g., ____)” (Style manuals 336).


The 3-em dash (———). “In a bibliography, a 3-em dash followed by a period represents the same author or editor named in the preceding entry” (Style manuals 336).

From the examples on page 336:

McCloskey, Deidre N. The Bourgeois Virtues.Chicago: University ofChicago Press, 2006.

———. Crossing:  A Memoir.Chicago: University ofChicago Press, 1999.


kiraKira McFadden is an avid enthusiast for all things publishing and writing. She has worked for two publishing firms and has helped local authors compile information for their works. You can visit her at



Is an older (2003) copy of CMS okay or is the latest edition best?



    Language is always changing, as are the rules applied to it. English is a very dynamic language–I realize the Chicago Manual of Style is very expensive, and it can be difficult to buy every copy. My suggestion would be to use their Website ( to reference some of the biggest changes, or things you might have questions about. The seventh edition, which I believe was the one published in 2003, is pretty out-dated, so you may want to rely on the Website more than your physical copy of the manual.

    Please let me know if you have any other questions.


Lauren Clark

Useful advice as always! You rock Kira! xx




    I’m glad I could help! Shoot us a question if you have any!


Donna Brown

This is so helpful, Kira! I’m definitely going to keep checking back weekly!




    I’m glad I could help, Donna. If you have any questions you want to see answered, we’d love to see them!


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