Punctuation

Commas | Dates | Colons | Quotation Marks | Apostrophe | Dashes and Hyphens

Commas

Serial comma
To avoid ambiguity writers should use a comma between the last two items in a series

The college will host the conference, which will feature a keynote address, lectures, and a poster display.
The U.S. flag colors are red, white, and blue
Avoid ambiguity: With gratitude to my parents, Mother Teresa and the Pope. (use the serial comma)

In numbers
Place a comma after digits signifying thousands: 1,930 students. (Exception: Don't use a comma when referring to temperature: 1800 degrees.)

i.e. and e.g.
Introductory words or phrases such as namely, i.e., and e.g., should be immediately preceded by a comma or semicolon and followed by a comma.

Local cheese is fresher, i.e., it doesn't have to be trucked here from Wisconsin. 

Dates

When writing a date, place a comma between the day (if given) and the year, and after the year.

December 7, 1941, is a day that will live in infamy.

Do not place a comma between the month and year when the day is not mentioned, or between season and year.

December 1999, fall 2000

Use a comma between two or more adjectives when each modifies a noun separately.

My uncle is a strong, confident, stubborn man.

Do not use commas between cumulative adjectives. In the instance below 'and' cannot be inserted between the adjectives three, oval, and disks, and the order of the adjectives cannot be changed.

Three large oval disks appeared in the sky above the city.

Colons

Use a colon after an independent clause to direct attention to a list, an appositive, or a direct quotation of one or more paragraphs.

Students should always carry the following things: paper, pens, text books, and a positive attitude.
My roommate is guilty of two unhealthy habits: staying up late and poor eating.

Quotation Marks

Set quotation marks outside of periods, question marks, and commas and inside colons and semicolons. They should be set inside of exclamation points that are not part of the quotation.

He asked, "How long will this take?"

No quotation marks are necessary in interviews when the name of the speaker is given first, or in reports of testimony when the words question and answer or Q and A are used, such as:

Q: Who will benefit from the fee waiver program?
A: Full-time faculty and staff.

Apostrophe

When referring to years, use an apostrophe only to indicate numerals that are left out. Do not use an apostrophe in plural cases. For class years, us a single, left facing single quotation mark with no comma between the last name and class year.

Joe Smith '98
1960s
the '90s (preferred style is the 1990s)

Master's and doctor's degrees should always be written with an 's. Never write masters' degrees.

Em Dashes, En Dashes, and Dashes/Hyphens

Em dash
Use em dashes to indicate an abrupt change of thought or to set off a parenthetical phrase with more emphasis than commas, or to set off an appositive whenever a comma might be misread as part of a series. Do not insert a space before or after em dashes. The sentence should still make sense if you remove the words between the em dashes.

In North Carolina, the amount of open space—farmland, mountains, and forests—provides unsurpassed opportunities for enjoying the outdoors.

En dash
Use en dashes to replace the word "to" when it represents a duration of time. Do not put a full space before or after the en dash. Do not use the en dash when preceded by the word "from."

The biology class will be held 2-4:30 p.m. on Tuesdays.
The biology class will be held from 2 to 4:30 p.m. on Tuesdays.

Hyphen -
Use the hyphen to connect two or more words functioning together as an adjective before a noun (to avoid ambiguity).

on-campus housing, rather than on campus housing.
Do not use the hyphen to connect -ly adverbs to the words they modify.
The beautifully exhibited artwork will be on display until the end of the month.

In a series, hyphens are suspended.

The Davidson runners received first-, second-, and third-place honors.

Use the hyphen with the prefixes all-, ex-, and self- and with the suffix -elect.

The college organizes several self-help projects to assist those in need.
Lily is the student government's president-elect.

Do not hyphenate words beginning with the prefix non, except those containing a proper noun.

Non-French, nontechnical

Do not place a hyphen between the prefixes pre, semi, anti, co., etc., and nouns or adjectives, except proper nouns. (Exception: Hyphenate to avoid duplicated vowels or triple consonants.)

coauthored, reapply, pro-republican, pre-enlist, premedicine

Do not place a hyphen between the prefix sub and the word to which it is attached, e.g., subtotal