To break a word at the end of a line. (Always split between syllables.)
Note: Although a hyphen is correct in this function, I strongly advise against splitting words at the end of lines. It is a better
practice to simply start the word on the next line. Leave the typesetting to typesetters.
Beyond the Basics
 Numbers: hyphenate numbers twenty-one through ninety-nine
Three hundred and thirty-five
Also take a look at these examples (see  Compounds)
some forty-odd pieces or so
 Fractions: hyphenate in noun, adjective, and adverb forms except when the second element is already hyphenated
Exception: When discussing the individual parts, do not hyphenate
We cut the pizza into four quarters; Dave took three quarters and Jan took one.
Note: Compounds formed with fractions are treated per rule --hyphenated only when adjectival and preceding the noun
an eight note
 Prefixes or suffixes: normally joined to the root without a hyphen
E.g.: ante, anti, bi, bio, co, counter, cyber, extra, hyper, infra, inter, intra, macro, mega, meta, micro, mid, mini, multi, neo, non, over, post, pre,
pro, proto, pseudo, re, semi, socio, sub, super, supra, trans, ultra, un, under
Exception 1: If doing so would double A's or I's (but not O's, or E's)
anti-intellectual ("i" next to an "i"--a hyphen is needed
anticrime (no hyphen needed)
antianxiety (no hyphen needed)
proactive ("o" next to "a", no hyphen)
preemployment ("e" next to "e", no hyphen)
coordinate ("o" next to "o", no hyphen)
Exception to [Exception 1]: co-op, de-emphasize
Exception 2: If doing so would triple a consonant
fall-like weather (3 L's-hyphen needed)
childlike enthusiasm (no hyphen needed)
Exception 3: If the resulting word might be misread
Exception 4: If the resulting word be a homograph (spelled the same as a different word)
re-creation (meaning to create again) recreation (meaning enjoyment)
re-lease (to lease again) release (to set free)
Exception 5: If the root is capitalized
Exception 6: ex (meaning former), all, half, self --generally hyphenated (before or after a noun) unless already a single word (a closed compound)
half-asleep, half-dollar (but halfhearted, halfway, etc.--check your dictionary to determine closed compounds)
self-control (exceptions: selfish, selfless)
Exception 7: quasi (only when used as an adjective)
quasi-scientific discovery (adjective)
a quasi success (noun--so no hyphen)
Exception 8: repeated terms in a double prefixes
Exception 9: before a compound term
 Compound modifiers that modify a noun: two or more words that together express a single idea are hyphenated if they precede a noun.
(Primary reference for this entry was Bartleby.com & Chicago Manual of Style)
open-mouthed kiss ("open" modifies "mouthed," not "kiss")
ill-tempered dog Note: these last two examples are a word joined to a past participle. Always hyphenate when preceding a noun.
well-known poet (would not be hyphenated if it followed the noun. E.g., The poet is well known)
ill-advised rescue (The rescue attempt was ill advised.)
high-quality jewelry (adjective+noun)
real-life experience (adjective+adjective)
better-looking car (comparatives -er)
best-running motor (superlatives -est)
over-the-counter drug (adjectival phrases-hyphenated when preceding a noun)
she gave me a come-on-over-and-give-me-a-kiss look Phrases used as adjectives preceding a noun
quicker-then-usual reply Note: familiar phrases are usually hyphenated regardless of function or position
Stop being a stick-in-the-mud. (hyphenated because it is a familiar phrase, otherwise would not have been)
a per diem allowance Exception: foreign phrases are not hyphenated
four-year-old boy Note: age terms are hyphenated in both noun and adjective forms
a four-year-old "
hydrogen chloride solution Exception: chemical terms are not hyphenated
Colors: considerable disagreement abounds regarding colors. The three theories are as follows:
1. Chicago Manual- color compounds are not hyphenated (except established expressions like black-and-white appearing before a noun
2. American Heritage Book of English Usage- color compounds are always hyphenate (except -ish, which is only hyphenated when
preceding the noun (Words Into Type agrees with this usage)
3. Treat color compounds like any other compound modifier and only hyphenate when acting as an adjective preceding a noun
Test: one of the two (or more) modifiers should not make sense (in the original context) if paired alone with the noun. If it does, you are dealing with
either coordinate or cumulative adjectives and should not hyphenate.
She wears high-quality jewelry. ("high jewelry"--does not make sense.)
He wore a blue wool sweater. ("blue sweater" and "wool sweater" both make sense. These are cumulative adjectives. No hyphen.)
Exception 1: If the adverb in an adverb/adjective or participle compound ends in -ly don't hyphenate.
carefully worked canvass
finely tuned machine
brilliantly crafted plan
Exception 2: don't hyphenate after very, most, least, more, less
very conservative views
most efficient method
least skilled artist
Exception 3: if the compound modifier is universally known and understood and/or there is no possible confusion of misreading, don't hyphenate.
high school class (Universally understood)
chocolate chip cookie "
third world country
income tax form
Exception 4: compound modifiers formed completely of capitalized words should not be hyphenated.
African American child
Exception 5: if the compound is itself modified, don't hyphenate.
Dave is a hard-working cop.
Dave is an extremely hard working cop. (No hyphen)
Exception 6: If the hyphen would look clumsy, it can be omitted, assuming no confusion results. (This generally applies to names.)
bubonic plague outbreak
chemical engineering degree
Exception 7: number + possessive noun- not hyphenated
one week's pay
three hours' work
Special Note: If the compounded adjective ends in a -d then omit the d
freckle-faced boy (instead of freckled-faced boy) the boy with the freckled face
dimplecheeked girl (instead of dimpled-cheeked girl) the girl with the dimpled cheeks
Note: remember, compounds are not hyphenated if they follow the noun instead of precede it.
Exception: some compounds are considered permanent and are hyphenated even if they follow the noun they modify.
(these are best identified via dictionary)
Style option: compounds can also be hyphenated when they follow the verb "to be." (check your publisher's style sheet)
That plan is short-sighted.
 Compounds with specific terms
(Reference: Chicago Manual of Style)
ache- always closed. E.g. toothache, stomachache
all- adjectival phrases hyphenated before or after a noun, adverbial phrases open. E.g. all-out effort, all along
book- open unless in the dictionary. E.g. coupon book, reference book, checkbook, cookbook
borne- normally closed, but hyphenated after words ending in b and after words of three or more syllables. E.g.waterborne, mosquito-borne, cab-born
century- standard compound modifier- hyphenate when acting as an adjective and preceding a noun. E.g twentieth-century literature
cross- noun, adjective, and adverb forms hyphenated, except some permanent compounds. E.g cross-reference, cross-country, crossbow
e- hyphenate. E.g. e-mail, e-commerce
elect- usually hyphenate unless the name of the office consists of two or more words. E.g. Mayor-elect, county assessor elect
ever- hyphenate before a noun (except some permanent compounds): ever-ready help, everlasting
ex- hyphenate. E.g. ex-wife
fold- closed unless formed with a hyphenated number. E.g. fourfold, twenty-five-fold, 150-fold
foster- standard compound modifier (hyphenate when acting as an adjective preceding the noun. E.g. foster mother, foster-family background
 Compounds by type
Compass points- closed unless three are combined.
Note: when the dash is taking the place of the word to it should be an en dash
The river runs north--south. ("--" is used, somewhat incorrectly here, do represent an en dash instead of a hyphen)
Grand-grandmother, grandfather (always a closed compound, regardless of position or function)
Great-great-grandmother (always hyphenated, regardless of position or function)
Stepmother (always a closed compound, regardless of position or function)
Half sister (open as a noun, hyphenated as an adjective preceding a noun)
Foster mom, foster-family background (open as a noun, hyphenated as an adjective preceding a noun)
 Normally open compound nouns: may be hyphenated for clarity if preceded by an modifying adjective.
(Primary reference for this section was Bartleby.com)
wine cellar (no hyphen)
underground wine-cellar (add a hyphen because of the preceding adjective)
Exception: when a compound modifier begins with an ly adverb, no hyphen is used.
freakishly dressed punk star
Note: some nouns are permanently hyphenated, regardless of position or modifiers. (Refer to dictionary)
 To indicate something spelled out
The banner read "W-i-l-l-y-o-u-m-a-r-r-y-m-e."
No spaces before or after.
Hanging hyphen: when the second part of the hyphenated expression is omitted, the hyphen is retained
fifteen- and twenty-year mortgages
five- to ten-minute intervals
both over- and underfed cats
en dash in place of a hyphen in a compound adjective when one or more of its elements is an open compound or when two or more of its elements are
post--World War II decades
a nursing home--home care policy
a quasi-public--quasi-judicial body
Let's Talk Style
Let's see how the pros use it