Using Hyphens

Hyphens are used to link words that function as a single adjective before a noun.  They are used with compound numbers, and to avoid confusion or awkward letter combinations.  Hyphens are also used with certain prefixes and suffixes and in certain special cases.

Using the hyphen in spelling for linking between words of compound nouns, verbs and adjectives

•    Compound words are composed of two or more words that express one concept together (shown in bold below). They may function as nouns, verbs, or adjectives in the sentence. Compounds come in three forms: open compounds are written with separate words, hyphenated compounds use hyphens, and closed compounds are written as one word.
doing a night shift, the butterfly’s life cycle, suffer from side effects, "She is his partner in crime" (nouns), drop in for a visit, stick up a bank (verbs)
[open compounds]

act as a stand-in, call for a time-out, She’s a stick-in-the-mud (nouns), a clear-cut decision, a  long-term plan, a two-way street, a water-resistant watch (adjectives), to cold-shoulder someone (verbs)
[hyphenated compounds]

a handbook, be at a standstill (nouns), a longtime friend, a clearheaded woman, a twofold increase (adjectives), to crossbreed species, to handwrite a letter (verbs)
[closed compounds]

•    It is usually difficult to guess what form the compound will take. The solution is to always consult a reliable dictionary, but also take into account that different dictionaries may suggest different forms. This is due to the language constantly changing. Rules regarding compound adjectives will be discussed in our review about the hyphen in punctuation.

•    Tip: The older a compound is in use, the more chances to it being written in one word, and vice versa. The hyphenated version tends to be a mid-way stage.
•    If one part of the compound is a single letter, it is usually open or hyphenated. The compound email is an exception that has turned into a closed compound, due to pervasive usage.
the H-bomb, y-axis, U-turn
[hyphenated compounds]

F distribution, V neck, X chromosome
[open compounds]

•    Do not hyphenate phrases originating form foreign languages, particularly Latin.
a priori, post hoc, vice versa

Pay attention!
•    The following are commonly hyphenated by mistake, but should be written without hyphens.
more or less, ongoing, under way

Use Hyphens to Avoid Confusion

Use hyphens whenever a prefix would create an ambiguous word.  For example, after you do something you can redo it.  However, if you fine someone, you would have to re-fine them (because refine means something else).

Use Hyphens to Avoid Awkward Letter Combinations

Use a hyphen after a prefix to avoid repeating the same letter too many times.  Here are some examples:

  • Re-engineer, pre-existing, semi-interested

Using the Hyphen in Spelling for Linking a Prefix or Suffix to a Word

•    Most prefixes and suffixes are attached to the root word without a hyphen. In some cases, two versions are acceptable (nonaggressive/non-aggressive, infra-red/infrared), but the tendency nowadays is to omit the hyphen.

Only in the cases below should the hyphen be used.

•    Use a hyphen after the prefixes all-, ex-, quasi-, and self-. Don’t use a hyphen when self is the root word.
Yes: All-inclusive, ex-husband, self-esteem
No: selfishness, selfless

•    Use a hyphen before the suffixes –elect, -odd, and -free.
the president-elect, thirty-odd students, sugar-free

•    Use a hyphen when the root word is a numeral.
pre-1900s, under-18s

•    Use a hyphen when the root word is capitalized.
pre-Columbian, pre-Reformation, Buddha-like

•    Use a hyphen to avoid an awkward looking string of letters.
No: antiintelectual, shellike, multititled, intraarterial
Yes: anti-intellectual, shell-like, multi-titled, intra-arterial

•    Use a hyphen if the word would have a different meaning without the hyphen.
The star football player has resigned. (quit)
The star football player has re-signed. (will continue working)

•    Use a hyphen if the word would be difficult to read if it weren’t hyphenated.
Coinventor may be read as coin ventor, so write co-inventor
Doubale may be read as doub le, so write do-able

•    Use a hyphen when the parts of the compounds are not commonly used together.
Common compounds: worldwide, clockwise
Unusual compounds: community-wide, nutrition-wise


Using the Hyphen to Avoid Word Repetitions

•    If you use a word more than once in one sentence, each time with a different modifier, consider using a suspension hyphen. However, do not overuse the hyphen in this role. If the repeated word comes last in the compound, write the full compound at the end, and hyphens in the earlier combinations.
Clumsy: He was referred to both clinic-based services and hospital-based services.
Better:   He was referred to both clinic- and hospital-based services.

Clumsy: You can either choose a two-month program, a three-month program, or a four-month program.
Better:   You can either choose a two-, three, or four-month program.

•    If the repeated word is the first part of the compound, write the full compound in the beginning and use hyphens for the next combinations.
The company-initiated and -sponsored events must be attended by all employees.

The Hyphen: Summing it up

This has been our review on the hyphen in punctuation. For better spelling, it is no less important that you read our review about the hyphen’s roles in spelling. These include:
•    Linking between words of compound nouns and verbs
•    Linking a prefix or suffix to a word
•    Linking words that represent numbers

Using the Hyphen for Indicating End-of-line Word Breaks

•    Most writers today use a word processor that automatically aligns text so that no end-of-line-word-break is needed. Read this section if you are still using a typewriter or have to adhere to certain type-set requirements that make it impossible to avoid such breaks.

•    We usually see end-of-line-word-breaks in printed books and newspapers, where a word is too long to fit on a line. Some amusing word-breaks have been noted in print media, such as the-rapist, men-swear, or mans-laughter. To avoid such embarrassing or other unclear word-breaks, follow the rules below:

•    Break words only between syllables. Consult a dictionary that indicates syllable division within a word. As dictionaries of US and UK English differ on this point, be consistent in style.
No: ent-ertain, proc-eed
Yes: enter-tain, pro-ceed

•    Do not break short words, one-syllable words, or words pronounced as one syllable, regardless of how long these are.
No: we-alth, school-ed, en-vy
Yes: wealth, schooled, envy

•    Do not break a word if only one or two letters will be left on a line.
No: a-lone, funn-y, discov-er
Yes: alone, funny, dis-cover or disco-ver

•    Break between two consonants according to pronunciation.
No: ful-lest, furnit-ure, referr-ing
Yes: full-est, furni-ture, refer-ring

Note: The following three rules are not compulsory but highly recommended.

•    Break compound words at the hyphen, or between the words (in closed compounds).
No: by-prod-uct, com-monplace
Yes: by-product, common-place

•   Break words that contain prefixes and/or suffixes, between these and the root word, not breaking any of the words' components themselves.
No: bro-therhood, superflu-ous
Yes: brother-hood, super-fluous

•   Do not break a word if the two resulting parts are words themselves, but are unrelated.
No: bin-go, are-as, prose-cute
Yes: bingo, areas, prosecute

Using a Hyphen in Spelling for Linking Words that Represent Numbers

•    Use a hyphen with any two-word number (21-99) or fraction.
thirty-two, two hundred fifty-six, one-quarter, 2 and two-thirds

•    If the fraction includes a two-word number, hyphenate only that two-word number, as more hyphens may make the fraction unclear
No: forty-five-hundredths
Yes: forty-five hundredths

•    Use a hyphen with any two-word number (21-99) or fraction.
thirty-two, two hundred fifty-six, one-quarter, 2 and two-thirds