From Wikipedia, the free encyclopedia
A hyphen ( -, or ‐ ) is a punctuation mark. It is used both to join words and to separate syllables. It is often confused with a dash ( –, —, ― ), which is longer and has a different function. Hyphenation is the use of hyphens.
Rules and customs of usage
A definitive collection of hyphen rules does not exist. Therefore, the writer or editor should consult a manual of style or dictionary of his or her preference, particularly for the country in which they are writing. The rules of style that apply to dashes and hyphens have evolved to support ease of reading in complex constructions; editors often accept deviations from them that will support, rather than hinder, ease of reading.
- Except for noun-noun and adverb-adjective compound modifiers, when a compound modifier appears before a term, the compound modifier is generally hyphenated to prevent any possible misunderstanding, such as twentieth-century invention, cold-hearted person, and award-winning show. Without the hyphens, there is potential confusion about whether "twentieth" applies to "century" or "invention", and similar.
- Hyphens are generally not used in noun-noun or adverb-adjective compound modifiers when no such confusion is possible; for example:
- government standards organization and department store manager
- wholly owned subsidiary and quickly moving vehicle (because the adverbs end in ly)
- Hyphenation is also common with adjective-noun compound modifiers but, arguably, less generally. Examples are real-world example and left-handed catch. Where the adjective-noun phrase would be plural standing alone, it usually becomes singular and hyphenated when modifying another noun. For example, four days becomes four-day week.
- Two-word names of numbers less than one hundred are hyphenated. For instance, the number 23 should be written twenty-three, and 123 should be written one hundred [and] twenty-three. (The and is normally included in British, Australian and New Zealand English but often omitted in American English.)
- Hyphens are occasionally used to denote syllabification, as in syl-lab-i-fi-ca-tion. Most American dictionaries use an interpunct, sometimes called a "middle dot" or "hyphenation point", for this purpose, as in syl·lab·i·fi·ca·tion.
- Hyphens are sometimes used in English to denote syllable breaks, particularly for prefixes, as when a (repeated) vowel is pronounced on its own rather than being silent or merged in a diphthong, as in 'co-operate' and 're-enlist' or even 'de-ice' and 're-ink', where some other languages (and some English authorities) use a diaresis like this: 'noël' or 'coöperate'.
- Some words are hyphenated to distinguish them from other words that would otherwise be homographs, such as "recreation" (fun or sport) and "re-creation" (in forensics), or "predate" (what a predator does) and "pre-date" (to be of an earlier calendar date).
- If a word begins on one line of text and continues into the following line, a hyphen is usually inserted immediately before the split. Note that the details of doing this properly are complex and language-dependent and that they interact with other typesetting practices: see justification and hyphenation algorithm.
- Some married couples compose a new surname (sometimes referred to as a double-barrelled name) for their new family by combining their two surnames with a hyphen. Jane Doe and John Smith might become Jane and John Smith-Doe, or Doe-Smith, for instance. In some countries, however, only the woman hyphenates her birth surname, appending her husband's surname.
- A hyphen may be used in quotations to imply the spelling of a word such as "W-O-R-D spells word."
- Hyphens are used to connect numbers and words, whether numerals or written out, as in 28-year-old woman (cf. twenty-eight-year-old woman) or 36-year veteran, in forming adjectival phrases. This is particularly used when forming adjectival phrases for weights and measures, such as "98-pound weakling" or "320-foot wingspan." The SI recommends against this practice when using metric units.
- They are also used in spelled-out fractions used as adjectives (but not as nouns), such as 'two-thirds majority' and 'one-eighth portion'.
The use of the hyphen has, in general, been steadily declining, both in popular writing and in scholarly journals. Its use is almost always avoided by those who write for newspapers, for advertising copy or for labels on packaging, since they are often more concerned with visual cleanliness than semantic clarity; the words are left with spaces. However, it is still used in most (American) newspapers and magazines; hence, people remain accustomed to seeing and understanding its use. In other countries hyphens are dropped in favour of connecting the two-word compounds.
Traditionally an en dash ('–') replaces the hyphen in hyphenated compounds if either of its constituent parts is already hyphenated or contains a space.
Examples of usage
Some strong examples of semantic changes caused by the placement of hyphens:
- disease causing poor nutrition, meaning a disease that causes poor nutrition
- disease-causing poor nutrition, meaning poor nutrition that causes disease
- a man-eating shark is a carnivorous fish
- a man eating shark is a male human in the active process of consuming a shark.
Additional examples of proper use:
- text-only document or …document that is only in text
- Detroit-based organization or …organization that is based in Detroit
- state-of-the-art product or …product is state-of-the-art (product is an advanced state does not contain hyphens)
- board-certified strategy or …strategy that is certified by the board
- thought-provoking argument or …argument that provokes thought
- time-sensitive error or …error that is sensitive to time
- case-sensitive password or …password that is sensitive to case
- government-issued photo ID or …photo ID that is issued by the government (…is issued by the government does not contain hyphens)
- light-absorbing material or …material that absorbs light
- award-winning novel or …novel that won an award or multiple awards (but, more likely, …won an award with no hyphen)
- web-based encyclopedia or …encyclopedia that is based on the web
- fun-loving person or …person who loves fun
- how to wire-transfer funds or …how to transfer funds by wire
- how to tax-plan or …how to plan for taxes
- advertising-supported service or service that is supported by advertising
- Rudolph Giuliani is an Italian-American (but see hyphenated American)
- list of China-related topics …list of topics that are related to China
- out-of-body experience
- near-death experience
- in surnames, for example Dominique Strauss-Kahn
Origin and history of the hyphen
In medieval times and the early days of printing, the predecessor of the comma was a slash. As the hyphen ought not to be confused with this, a double-slash was used, this resembling an equals sign tilted like a slash. Writing forms changed with time, and included the full development of the comma, so the hyphen could become one horizontal stroke.
However, publishers of dictionaries liked that a tilted symbol would give them a little extra room in their books. Those dictionaries based on the second edition of the Merriam-Webster dictionary used one small, slightly tilted slash for a hyphen which they added at the end of a line where they broke the word, but used a double-slash much like the very old symbol to indicate a hyphen which needs to be in a phrase and just happened to get at the end of the line. This double-slash would be used in hyphenated phrases in the middle of the text as well, so that there would be no confusion.
Hyphens in computing
In the ASCII character encoding, the hyphen was encoded as character 45. Technically, this character is called the hyphen-minus, as it is also used as the minus sign and for dashes. In Unicode, this same character is encoded as U+002D so that Unicode remains compatible with ASCII. However, Unicode also encodes the hyphen and minus separately, as U+2010 ( ‐ ) and U+2212 ( − ), respectively, along with a series of dashes. Usage of the hyphen-minus character is discouraged where possible, in favour of the specific hyphen character.
When flowing text, it is sometimes preferable to break a word in half so that it continues on another line rather than moving the entire word to the next line. Since it is difficult for a computer program to automatically make good decisions on when to hyphenate a word the concept of a soft hyphen was introduced to allow manual specification of a place where a hyphenated break was allowed without forcing a line break in an inconvenient place if the text was later reflowed. Soft hyphens are most useful when the width is known but future editability is desired, as few would have the patience to put them in at every place they believed a hyphenated split was acceptable (as would be needed for their meaningful use on a medium like the Web).
When flowing text, a system may consider the soft hyphen to be a point at which a word may be broken, and display a hyphen at the end of the broken line; if the line is not broken at that point the hyphen is not displayed. In most parts of ISO-8859 the soft hyphen is at position 0xAD, and since the first 256 positions in unicode are taken from ISO-8859-1, it has a unicode codepoint of U+00AD. In HTML, the soft hyphen is encoded as the character entity "
Most text systems consider a hyphen to be a word boundary and a valid point at which to break a line when flowing text. However, this is not always desirable behavior, especially when it could lead to ambiguity (such as in the examples given before, where "recreation" and "re-creation" would be indistinguishable). For this purpose, Unicode also encodes a non-breaking hyphen as U+2011 ( ‑ ). This character looks identical to the regular hyphen, but is not treated as a word boundary.
The ASCII hyphen-minus character is also often used when specifying parameters to programs in a command line interface. The character is usually followed by one or more letters that indicate specific actions. Typically it is called a dash in this context. This is used in many different operating systems, particularly Unix and Unix-like systems. DOS and Microsoft Windows also sometimes make use of the hyphen, although the use of a forward slash (/) is more prevalent there. A parameter by itself that is only a single hyphen without any letters usually means that a program is supposed to handle data coming from the standard input or send data to the standard output. Two hyphen-minus characters ( -- ) are used on some programs to specify "long options" where more descriptive action names are used. This is a common feature of GNU software.
International Standard dates
Continental Europeans use the hyphen to delineate parts within a written date. Germans and Slavs also used Roman numerals for the month; 14‑vii‑1789, for example, is one way of writing the first Bastille Day, though this usage is rapidly falling out of favour. Plaques on the wall of the Moscow Kremlin are written this way. Usage of hyphens, as opposed to the slashes used in the English language, is specified for international standards.
International standard ISO 8601, which was accepted as European Standard EN 28601 and incorporated into various typographic style guides (e.g., DIN 5008 in Germany), brought about a new standard using the hyphen. Now all official European governmental documents use this. These norms prescribe writing dates using hyphens: 1789-07-14 is the new way of writing the first Bastille Day.
This method has even gained influence within North America. This is due to the fact that most common computer filesystems make the use of slashes difficult or impossible. Windows uses the \ as the directory separator, and / (which is used for switches to commands) is also forbidden. Unix-like systems use / as a directory separator and while \ is legal in filenames it is awkward to use as the shell uses it as an escape character. The non-year form is also identical apart from the separator used to the standard American representation. The ISO date format is also sorted correctly by a dumb sort routine which can be useful in many computing situations including the aforementioned filenames. Many computer systems and IT technicians have switched to this method. The government of the Commonwealth of Massachusetts, for example, has switched to this method, although it has not yet been imposed upon society at large.
- Hyphen War
- Double hyphen
- Economist Style Guide — Hyphens
- Jukka Korpela, Soft hyphen (SHY) - a hard problem?
- Markus Kuhn, Unicode interpretation of SOFT HYPHEN breaks ISO 8859-1 compatibility. Unicode Technical Committee document L2/03-155R, June 2003.
- Igor Podlubny, On-line Hyphenator (hyphenates Slovak)