Hyphen

[abochittah]

HYPHENS

Hyphens cause writers more trouble than any other form of punctuation, except perhaps commas. This may be because the hyphen has no analogue in speech; it is punctuation created purely by the needs of print.
Uses of the hyphen
1. The most common use of the hyphen is to divide words that do not fit on a justified line of type. Most computerized typesetters have internal dictionaries that will automatically hyphenate. These dictionaries are limited, however, and words that are not in the dictionary are hyphenated according to certain mathematical rules that cannot take into account the vagaries of English. If you are working on a system that shows how words will break when type is justified (sometimes called the Hyphenate and Justify function), you should allow yourself time to check word breaks to make sure the hyphens are in the proper place.
Examples: The mathematical rules of the computer usually tell it to break words between prefix and root word. However, the computer cannot distinguish between the pre- of preordained and the pre- of pressmen. It also cannot distinguish between verbs and nouns, which can be hyphenated differently (e.g., re-cord [verb] and rec-ord [noun]; pro-gress [verb] and prog-ress [noun]).
2. The more complicated use of hyphens involves compound words. This is a spelling as much as a punctuation question.
Compound words are terms made up of two (or more) words that are described as open (meaning they consist of two separate words that are closely associated as one concept, such as real estate, high school, civil rights), hyphenated (ill-favored, kilowatt-hour, mass-produce), or solid (meaning the two words, which were originally separate, are now spelled as one word, with no hyphen, such as makeup, bookstore, goodwill).
Compound words are also considered to be either temporary or permanent. A permanent compound is one that will be in a dictionary, and it is these words whose spelling may differ from dictionary to dictionary (good will, good-will, goodwill). A temporary compound is one that is created by the writer for a particular use and will probably not be in any dictionary. However, if the temporary compound gets picked by other writers who see a need for it and it gets used enough, it will eventually appear in dictionaries.
The tendency is for compounds to begin life as two-word or hyphenated terms, and when they have become acceptable in general usage and gotten into dictionaries, they lose the hyphen and are spelled solid, as one word. This is a tendency, not a rule. Don't rush into dropping the hyphen too quickly, but be aware that the tendency does exist.
Some permanent compounds become "uncompounded" if an adjective must be hyphenated to part of the original compound. While bookstore is a permanent compound (spelled solid in most dictionaries), a store that sells used books would not be called a used bookstore; that would refer to a bookstore that was used. Used, in this case, refers only to the book part of the compound word, so such a store would be called a used-book store.
Function of the Hyphen
The point of the hyphen is to avoid ambiguity for the reader. If a temporary compound is used as an adjective before a noun, it may be unclear what words are modifying what: is a free form sculpture a sculpture that is free, or a sculpture that is free in its form? If the latter, adding the hyphen between free and form makes the meaning instantly clear. The ambiguity occurs because we expect a noun to follow free, and form is a noun, but in this particular case free and form constitute an adjective describing sculpture. (In this particular case, the adjective free-form precedes the noun. When the temporary adjective follows the noun, there is no need for a hyphen. For example: The sculpture on the terrace was free form.)
Classification
There are three grammatical kinds of compound words: noun forms, adjective forms, and words formed with prefixes. (This section is freely adapted from the excellent chart in the Chicago Manual of Style.)
Noun forms

1. Temporary words formed with master are generally spelled open, although some have attained the status of permanent: master builder, master artist, but masterwork, masterstroke.
2. Words of relationship + noun are spelled open: fellow officer, sister ship, mother figure, parent organization
3. Quasi noun compounds are spelled open, but when they are used as adjectives, they are hyphenated whether they precede or follow the noun: quasi scholar, but quasi-scholarly work
4. Two-word occupations are spelled open: attorney general, postmaster general
5. Temporary compounds with vice may be spelled open or hyphenated. Chicago Manual of Style advises that all be hyphenated. AP Style Manual advises that all be spelled open. Other style books specify which are spelled open and which hyphenated, the presumption being that all not specified follow the house dictionary. Vice president or vice-president ; vice admiral or vice-admiral
6. Noun + noun, in which each represents different and equally important functions, should be hyphenated: singer-songwriter, city-state
7. All -in-laws are hyphenated: sister-in-law, father-in-law
8. All great- relatives are hyphenated: great-great-grandmother
9. All self- compounds are hyphenated, whether nouns or adjectives: self-knowledge, self-educated
10. Nouns formed with -elect are hyphenated. If the office is made up of two or more words, style differs on whether to leave the entire compound open or hyphenate -elect only to the final term: county assessor elect or county assessor-elect
11. Combinations of words that include a prepositional phrase describing a character are hyphenated: Johnny-on-the-spot, stick-in-the-mud, ball-of-fire
12. Fractional numbers are hyphenated between the numerator and denominator, unless either number already contains a hyphen: one-eighth, thirty-one hundredths
13. Compounds with -ache are spelled solid: stomachache
14. Check your dictionary for compounds with -book and -house. Permanent ones, in the dictionary, are usually spelled solid: notebook, boathouse. Temporary ones are spelled open: recipe book, rest house

Adjective forms

1. NEVER hyphenate an adverb to an adjective. Adverbs ending -ly + adjective or participle are always spelled open: highly developed species, poorly understood work, dimly lit room, gravely ill child
2. Compounds formed with unhyphenated proper names are always open: Civil War literature, Latin American history, Old English alphabet

Do not confuse with prefix forms of proper names: Austro-Hungarian empire, Russo-Japanese war, Sino-Soviet split

1. Half- compounds are hyphenated, whether they precede or follow the noun, except for a few permanent compounds (check your dictionary): half-asleep, half-timbered, but halfway, halfhearted

All- and self- compounds are also hyphenated, whether they precede or follow the noun: self-righteous, self-inflicted, all-encompassing, all-powerful

1. Compounds formed with noun + present participle (-ing form of the verb) or adjective + past participle (-ed form of the verb) are hyphenated before the noun: thirst-quenching drink, rain-causing clouds, street-vending license, risk-based securities, straight-sided fences, fast-paced dialogue
2. Cardinal numbers + unit-of-measurement adjectives are hyphenated before the noun, whether the number is spelled out or is a figure: 10-foot pole, three-feet high, nine-millimeter pistol, 43-yard line. When a cardinal number, unit of measurement, and another adjective precede a noun, the entire term is hyphenated: 40-foot-long fence, 10-year-old girl, but The fence was 40 feet long; The girl was 10 years old.
3. Cardinal number + -odd adjectives are hyphenated before or after the noun: 60-odd, one-hundred-odd
4. Compound adjectives with well-, ill-, better-, best-, little-, lesser-, etc., are hyphenated when they precede the noun, unless the compound itself is also modified: little-known fact, best-seller list, well-intentioned acts, ill-favored man, but She is well known; very best tasting cake
5. Temporary adjectives with cross- are hyphenated, but check your dictionary for those that have become permanent and are spelled solid: cross-country, cross-eyed, cross-index, crosscut, crosswise, crossover
6. Phrases used as adjectives are hyphenated before the noun: up-to-date equipment, devil-may-care attitude, but The collection is up to date; He is matter of fact.
7. Foreign phrases used as adjectives are open: laissez faire policy, post mortem session, a priori assumptions
8. Adjectives of color are open: bluish gray sky, emerald green sweater, orangey pink lipstick, purple pink flowers
9. The suffix -like forms temporary compounds that are spelled solid, except when the root word is a proper name, ends with -ll, or is a two-word combination: dreamlike, coallike, roll-like, Quentin Tarantino-like, vacuum-bottle-like
10. Adjectives with -fold are spelled solid when the number is a word, but hyphenated when the number is a figure: threefold, 10-fold
11. Quasi- adjectives are hyphenated, whether they precede or follow the noun: quasi-religious courses
12. Chemical terms are spelled open: sodium chloride solution, sulfuric acid rinse

Prefixes
Usage differs depending on publication style. Chicago Manual of Style spells most compounds with the common prefixes solid (pre-, post-, over-, under-, pro-, anti-, re-, un-, non-, semi-, co-, pseud-, intra-, extra-, infra-, ultra-, sub-, super-, supra-). AP Style Manual is more choosy: pro- and co- are hyphenated when certain meanings are intended; anti- and non- are usually hyphenated, with some exceptions noted; post-, pre-, and over- follow the dictionary in general; and under-, un-, re-, semi-, intra-, extra-, ultra-, sub-, super-, and supra- are usually spelled solid. Both style books require hyphenation when the root word is a proper name or figures (anti-Semitic, pre-1989) and to distinguish homonyms (re-creation or recreation, un-ionized or unionized). In addition, AP requires a hyphen when the root word begins with the same vowel that the prefix ends in, with very few exceptions (re-election for AP, reelection for Chicago; pro-abortion for AP, proabortion for Chicago).
Words that are already hyphenated are joined to a prefix with a hyphen: un-self-conscious.
When in doubt, consult your style manual and/or dictionary.