Hyphens in Descriptions
Use hyphens for two-word descriptions that come before nouns (a good-natured wildebeest, an ill-tempered aardvark ).
Use hyphens with a series of descriptors that all refer to a single noun:
Waldo had both short- and long-term plans for world domination.
The judges provided the first-, second-, and third-order results of the waffle tossing competition.
Don’t use a hyphen with very, most, least, or less (as in a very large hippopotamus, the least accomplished professional, the most impressive fruit hat, a less appealing hot dog) or words that end in –ly (a totally new type of zombie, a fully destroyed dollhouse).
Also, if you could use either descriptive word on its own, don’t use the hyphen (a smart [and] young mime, a sweet [and] old platypus)
Hyphens with Prefixes and Suffixes
Use hyphens with prefixes such as ex (ex-leader), with numbers (pre-1980), and with abbreviations (pre-U.S. Civil War).
Hyphens are also typically recommended when adding prefixes or suffixes would create double vowels (anti-agrarian, ultra-ambitious) or double consonants (non-negotiable, shell-like). However, there are a number of exceptions to this rule. For example, the prefixes pre and re don’t require hyphens according to the somewhat arbitrary laws of punctuation (reenter, preempt). Additional prefixes that don’t require hyphens include:
- after (aftereffect)
- anti (antiestablishment)
- bi (biannual)
- co (coauthor)
- extra (extrasensory, extracurricular)
- inter (interpersonal)
- micro (micromanage)
- mini (miniseries)
- multi (multilingual)
- mid (midsentence)
- non (nonprofit)
- socio (socioeconomic)
- over (overprotective)
- under (underrepresented)
- post (postwar)
- pro (promarriage)
- semi (semistructured)
- sub (subpar, subcontract)
- super (supercharge, superannuated)
- ultra (ultramarathon, ultrachic, ultracareful)
Suffixes that don’t require hyphens include ache (toothache), less (formless), like (catlike, wavelike), and wide (citywide).
Some sources say that the rule about splitting up two vowels overrides the general rules for hyphen use and recommend adding hyphens to words such as anti-establishment, co-occur, and re-enter. When in doubt, go with personal preference or whatever style guide you’re working with and be consistent.
Also, use a hyphen in cases where adding a prefix without it would change the intended meaning (for example, re-form vs. reform, re-cover vs. recover, re-creation vs. recreation, re-petition vs. repetition, re-sent vs. resent, and un-ionized vs. unionized).
Hyphens for Family Members
Use hyphens with ex, in-law, and great (ex-wife, mother-in-law, great-uncle).
Don’t use hyphens with step, half, and grand (stepfather, half sister, grandmother).
Hyphens in Fractions
Hyphens are typically used in fractions such as four-fifths. However, there are no simple rules for half; in some words it is added without a space or hyphen (halfway); for others, a space is added (half brother) or hyphens are used (half-hour).
Hyphens for Breaking Words in Two
Splitting words should be avoided whenever possible. If there is no way to avoid it, break the word between syllables and into roughly equal parts if possible, and add a hyphen to show the spot where the word breaks. For example, if you have to break the word heartbeat, break it at heart- and continue with beat on the next line.
Dashes
The dash (often referred to as the em dash) is used to mark information that is provided as an aside (information that could also be placed in parentheses) or an interruption, though the dash may be used to emphasize information as well.
He went to the store — with my money — to buy Popsicles for his elephant.
I want everyone to write an essay on — Jane, stop eating paste.
Whether you choose to put spaces around the dash is a matter of personal preference (many sources recommend using spaces for better readability). Whatever you choose to do, do it consistently.
Note: Most word processing programs will create a dash if you type two hyphens in a row.
See the main Grammar, Punctuation, and Writer Resources pages for more tips and resources.
References:
- American Psychological Association. (2011). “Punctuating Around Quotation Marks.” Blog.APAStyle.org.
- Brians, P. (n.d.). Common Errors in English Language.
- Capital Community College Foundation. (n.d.). “Quotation Marks” and “Commas.” Grammar.ccc.commnet.edu.
- Fogarty, M. (2010). Grammar Girl: Quick and Dirty Tips.
- O’Conner, P. T. (1996). Woe Is I, the Grammarphobe’s Guide to Better English in Plain English. New York, G. P. Putnam’s Sons.
- OWL at Purdue. (2013). “How to Use Quotation Marks” and “Extended Rules for Using Commas.” The Writing Lab & the OWL at Purdue and Purdue University. OWL.English.Purdue.edu.
- Strauss, J. (2013). Grammarbook.com.
- The Guardian. (2013). “‘The British style’? ‘The American way?’ They are not so different.” TheGuardian.com.
- Trask, L. (1997). Guide to Punctuation. University of Sussex.