Punctuation
The word punctuation comes from the Latin pungere, “to puncture or prick.” A punctuation mark is a spot that has been pricked by an instrument (the past participle of pungere is punctus).
Ampersand
This symbol (&) comes from the Latin et (“and”). Scribes eventually linked the two letters “e” and “t” into a single squiggle. The name ampersand comes from the way children learned the alphabet by rote in the nineteenth century. It is really a mispronunciation of four separate words in one: “and per se and.” The character itself offers incredible graphic variety and delight from typeface to typeface.
Apostrophe
The main use for an apostrophe is in forming the possessive of a noun. Normally, adding an apostrophe and an “s” does this. The main exception is in plural words ending with an “s,” which only need an apostrophe after the last “s.” Keep in mind that if the word is italicized or underlined, the apostrophe and “s” are not italicized or underlined. You don’t use an apostrophe to form the plurals of words, including numbers (7s, 8s), years (1970s, ’60s), and acronyms (IPOs), unless not doing so creates great confusion (do’s and don’ts).
Asterisk
The word asterisk comes from the Greek asteriskos, “little star.” This flexible mark (*) can be used:
- to represent a letter left out of a word as an itemizer (in place of the bullets used in this list, for instance)
- to signal a footnote
- to represent the word born when preceding a date as a prompt sign in computerese (where it is called a splat)
Colon
A colon might be thought of as a divider. It can be used:
- to introduce a list, as it just was
- in place of such expressions as for instance, as follows, namely, to wit, viz, for example, and that is
- to introduce a quotation or extract in dialogue
- to separate minutes from hours
- to set off a salutation in a letter.
A colon is usually followed by a lowercase letter, especially if what follows is an incomplete sentence. It may, however, be followed by a capital if it introduces dialogue or a formal statement.
Comma
The word comma comes from the Greek komma (“segment, clause”), indicating a part of a sentence. In the fifteenth century it was also known as a tittle, from the Latin titulus (“label, title”). In early manuscripts commas appeared as a full slash mark, or solidus (/), but later shrank to today’s size.
Commas are used as needed for clarity: to separate thoughts from each other and to make sentences less unwieldy. Don’t get carried away. Too many pauses can interrupt the flow and slow down the reader. Here are some common uses:
- after a conjunction in a compound sentence
- to distinguish a nonrestrictive phrase or clause (one that could be omitted without changing the meaning)
- to separate three or more elements in a series
- to set off parenthetical remarks
- to separate month and day from year in month/day/year sequences
- to set off such expressions as namely, for example, and that is
- for words in apposition (unless they have a restrictive function), for example, “Mr. Gold, my neighbor,...”
Crosshatch
A printer’s term, also known as a double hash mark. The crosshatch (#) can be used as a substitute for the word number if it precedes the figure (#3) or a substitute for the word pounds if it follows a number (3#). It is also a proofreader’s sign for “space” and a prompt sign in computerese (where it is called a crunch).
Dagger
Also known as an obelisk (from the Greek obelos, “a spit, skewer”), the dagger (†) is used as a signal for a footnote or as an indication that a word is obsolete. It can also represent the word died if it precedes a date.
Dashes
There are two main kinds of dashes: the long em-dash and the short en-dash. There are also two-em and three-em dashes, but these are used infrequently (for missing letters and missing words respectively).
The em-dash is a full square of the type size. One of its main uses is to signal sudden changes in tone. Or it may be used instead of parentheses to set off a clause or phrase. In general, use the em-dash sparingly, for it attracts attention to itself and can be disturbing.
An en-dash is only one-half of the square of the type size and resembles a hyphen. It is used primarily to represent missing but implied items in a series (“2¬4” means the numbers 2 through 4).
Ellipses
Ellipses are three dots used to indicate the unfinished end of a spoken sentence or omission of a word or phrase from quoted material. If an entire sentence or paragraph is omitted, four dots should be used, with the first positioned as a normal period.
Exclamation point
Whenever the Romans wanted to say “gee-whiz “fantastic,” “wowee,” “cool,” or the equivalent, they said, “lo.” Scribes, saving precious space on the manuscript, wrote the two letters above each other, the “l” on top, the “o” beneath it. Soon the “o” filled in with ink and became a dot. Don’t punctuate your writing with lots of “screamers” or “bangs” to increase emphasis. It looks cheap and overblown. Instead, use them with discretion.
Hyphen
Hyphens link words together, but must be used with care because interpretation can be affected by the inclusion (or lack) of a hyphen. Follow the practice suggested by a good, up-to-date dictionary. Hyphens are also used when two words are joined to form an adjective that modifies a noun, such as computer-based training.
Italicizing and underscoring
Neither underscoring (also known as underlining) nor italicizing is strictly punctuation. But the fundamental purpose of punctuation is to help the reader to understand, and in a similar way underscoring and italicization offer clues to meaning.
If you must use underlining instead of italics, it should be uninterrupted; the whole phrase should be underlined, not just the individual words. But do not underline the final period or any other punctuation mark that ends the phrase or sentence.
Paragraph
Also known as a pilcrow or blind P, this symbol (¶) is used to represent a paragraph. It is most commonly used in legal work and editing.
Parentheses
Parentheses, nicknamed parens, are used for separating subsidiary phrases (or background information) from the flow of text. To enclose secondary parenthetical expressions within parentheses, use brackets (going from parentheses to brackets [like this]). Braces provide a third degree of enclosure or sign of aggregation—( [ { } ] )—but it is best to avoid this situation altogether.
All punctuation should occur inside the parentheses if the item is a full sentence. Avoid commas or semicolons before the opening parenthesis, unless the parentheses are used for numbers in a list.
Period
The word period comes from the Greek periodos meaning “cycle,” thus a complete thought or sentence. In the fifteenth century, the period was known as a jot, from the Greek iota.
Here are a few do’s and don’ts for periods:
- Use them at the end of a sentence, unless they are replaced with exclamation points or question marks.
- Don’t use them at the end of headlines or subheads. They mark the end of a thought and may discourage the reader from continuing reading. In the United Kingdom periods are called full stops for good reason.
- Don’t use them in lists when the items are short and not complete sentences. More complex items and complete sentences may require periods, as in this list.
Question mark
The Latin word quaestio (“I ask”) was shortened by space-saving scribes to “QO” and soon a “Q” above an “0.” The “Q” quickly degraded into a squiggle and the “O” into a little blob.
Quotation marks
In the United States quotation marks begin with a 66 (or sometimes a flopped 99) and end with a 99. Single quote marks are used for quotations within quotations. Guillemets (usually starting « and ending ») are used instead of quotes in French, Spanish, and Italian. Quotation marks are used:
- to set off direct dialogue
- to indicate a quotation from another source
- to denote irony or signal slang or obsolete terminology (but try not to overdo it and never use quote marks merely to give emphasis to an important word)
- to define letters or groups of letters discussed as letters
- for the titles of short poems, magazine articles, short stories, essays, comic strips, TV and radio programs, and songs (but the titles of books, long poems, periodicals, newspapers, movies, ballets, plays, paintings, and sculpture—as well as the names of airplanes, ships, and trains—are italicized)
Section
This symbol (§) indicates a subdivision of a paragraph in legal citations or a part of a chapter in a book.
Semicolon
Think of the semicolon as a break in continuity greater than that implied by a comma. Most frequently it is used to separate the two main clauses of a compound sentence when they are not linked by a conjunction. It is also used to separate items in a series when commas would not be clear enough.
Solidus
Also known as a slash, slant, shilling mark, diagonal, or virgule, the solidus originally functioned as a comma. Today its major uses are:
- separating the divisor from the dividend in fractions (1/2)
- separating the days, months, and years in dates (2/14/1987)
- implying the word per ($3/100)
- indicating choice (yes/no)
- indicating line ends when poetry is shown run-in (i.e., in a continuous stream rather than line by line).
Sometimes a vertical (|) bar may be used instead of the slanted solidus for aesthetic reasons.