Punctuation

"All punctuation exists, basically, to help readers understand what you wish to say." (Kane, 2000)

Each mark, its meaning and placement, has a high level of impact on the essay itself, guiding the reader through not only the written text, but also showing how that text should be read and interpreted. While a great number of the conventions pertaining to punctuation are not hard-and-fast rules per se, there are a few general guidelines for usage that should be learned to write more effectively. This section covers the most common forms of punctuation and provides notes for their use.

Apostrophe ('). One of the most misused (or underused) punctuation marks is the apostrophe. Apostrophes can be used for several purposes, such as showing the omission of letters within a word ("ma'am," "ne'er," "o'er," and so forth; contractions "I'm," "they're," "can't," "it's," (meaning "it is" not "belonging to it"); and possessives for singular nouns (using an apostrophe with "s") "her's," "Mike's," "America's," "Cinderella's," and so forth. In addition, plural nouns (using the apostrophe only at the end of the word that already ends with "s") "girls'", "gladiators'", "Serkis'", and others.

It is not necessary to use apostrophes with possessive pronouns, "his," "hers," "mine," "yours," "its," "ours," "theirs,"; showing plurality (that is, "There are a lot of donkey's here today." which is incorrect); or in conjunction with acronyms and abbreviations (write "CDs" instead of "CD's," "1800s" rather than "1800's," and others).

Colon (:). The colon is a type of internal punctuation, that is, it only appears inside a sentence, never at the end. Colons are "…Used after a statement that introduces a quotation, an explanation, an example, or a series. Also, the colon often appears after the salutation of a business letter and between numbers or groups of numbers in expressions of time…and ratios." (About.com, 2008)

Usage examples include, "There are three ingredients in Grandma Jenkins' chowder: clams, cream, and potatoes." "It was 6:00am and all was quiet on the Western Front." and "At Jasperdale College, the ratio of students to teachers is 15:1."

It is also useful to note that, for variety, colons can also be used as follows: "Standing in line: the most frustrating experience known to man." That is, the introductory statement is placed following the colon rather than in front of it, which is the more traditional construction.

Comma (,). The comma is another internal punctuation mark (that is, it can never end a sentence) that serves to separate ideas or items in a list.

Example. "Ron, Tom, and Jerry all ran for the parking lot to see what was going on."

Commas can be used to separate introductory words in a sentence, "In the land of the blind, the one-eyed man is king."

Finally, commas can be used to separate interruptive text, such as asides or other intrusions into the sentence.

Examples.
"I was at the mall the other day, and, of course, I ran into Hilda."
"The art of mathematics, according to Hendershott, is all in the numbers."

Dash (--). The dash has no function of its own. It sometimes can function as a very strong comma or "...A less formal equivalent to the semicolon, the colon, and the parenthesis." (Kane, 2000) Dashes can also demark interruptive text, "It was a sunny day--especially sunny for January--and the kids were all abuzz."

Exclamation point (!). Exclamation points are used at the end of a sentence to indicate strong emotion. They also can be used to immediately follow an interjection to show additional emphasis and feeling.

Period (.). Also known as an "end stop," the period marks the end of a sentence. "More exactly, it closes declarative sentences--those which state a fact, perception, idea, belief, feeling--and it may also close an imperative sentence, or command (though these are often punctuated with an exclamation point)." (Kane, 2000)

Periods are also used for abbreviations, such as "Mr.," "Mrs.," "Rev.," "Dr.,", and others. While they were previously used for abbreviations of organizations, government agencies, and so forth, they are now considered unnecessary. For example "F. B. I." is now abbreviated FBI (without periods or spaces).

Question mark (?). Sometimes called the "query" or "interrogation point," the question mark is the third and final punctuation that ends a sentence. It is used after direct and rhetorical questions, which are usually indicated by the use of the words "who," "what," "why," "when," "how," and so on, within the sentence. (Kane, 2000)

Quotation marks (" "). Quotation marks are used for "...(1) Direct quotations, (2) certain titles, and (3) words given a special sense." (Kane, 2000) Quotes can be double ("...") or single ('...'). In American usage, the single quotation marks are most often used for quotes within a quote. (Kane, 2000)

Semicolon (;). Semicolons are used to separate independent clauses within a sentence and sometimes delimit items in a list when any one of the items contains a comma.