Style Guide: Punctuation


Use a colon to introduce a quotation or a list provided that the clause before the colon is a complete sentence, which may include the words the following.

Correct: The class will cover the following: engine design, engine maintenance, and engine repair.
Correct: The new graphics equipment has impressive features: a color screen, a state-of-the-art printer, and a musical interface.
Incorrect: The class will cover: engine design, maintenance, and repair.

Do not use a colon after the verb to be or after the words such as or including.

Correct: On rainy days, we played board games such as Monopoly, Scrabble, and Trivial Pursuit.
Incorrect: He bought his course supplies at the Bookstore, including the graphing calculator, pencils, and notebooks. (Note: comma precedes including.)
Correct: He bought his course supplies at the Bookstore including: the graphing calculator, pencils, and notebooks.


Commas in a series

Use commas between items and before the word and.

Example: Researchers study animal, vegetable, and mineral substances

Commas after an introductory phrase

Use a comma after an introductory phrase unless the phrase is quite short.

Although we have applied for a federal grant, we do not expect that it will be funded.
Last year Durham Tech served over 30,000 citizens. (no comma necessary after year but acceptable)
During 2010, Durham Tech experienced enrollment increases.

Commas and semicolons in a series

When using commas in a series, the commas are replaced with semicolons when one portion of the series requires commas between items.

Correct: He asked for a new desk; an office with a view; and the latest computer hardware, software, and printer
Incorrect: He asked for a new desk, an office with a view, and the latest computer hardware, software, and printer.

Commas with quotations

Commas ALWAYS go inside the final quotation mark.

Example: “Stop screaming,” shouted the nerve-wracked mother.

Commas in dates and in headings

Use a comma to separate a complete date from the year and, in column headings, to separate a month or season from the year. Also, place a comma after the year in text.

June 16, 2014
In May 2013, several politicians visited the campus.
Application Procedures Spring, 2013 (in headings only — not in text copy)
We left June 16, 2013, to travel in Europe.


Use parentheses to set off non-essential information. Note that the period may be placed either inside the parentheses (if the information within the parentheses is a complete, independent sentence, which began with a capital letter) or outside the parentheses (if the information within the parentheses is a fragment).

Most of Durham Tech’s students are North Carolinians. (Of course, there are exceptions.)
The majority of our students are part time (working full or part time while enrolled).


Periods are to be used at the end of each complete sentence and at the end of each bullet in a list. Periods are not used in headlines or subheadings.

Punctuation with quotation marks

Commas and periods

ALWAYS place commas and periods inside the quotation marks.

When he heard the news, the reporter mumbled, “There goes my job.”
“Don’t question authority,” said the policeman.
In Shakespeare’s words, “A rose by any other name would smell as sweet. ”

Exclamation points and question marks

When they are a part of the quoted material or message, place exclamation points and question marks inside the quotation marks. Otherwise, they belong outside the quotation marks.

What did Martin Luther King, Jr., mean when he said, “I have a dream”? (question mark is not part of the quotation)
The instructor asked, “What is the meaning of life?” (question mark is part of the quotation)
Sergeant Parker exclaimed, “Stop smiling!” (exclamation point is part of the quotation)

Semicolons and colons

Semicolons and colons are placed outside the quotation marks or parentheses.

Example: President James remarked that the plan needed a “few minor adjustments”; however, he did not reject the plan entirely.

When a quoted statement ends with either a semicolon or colon, the colon or semicolon is dropped.

L. P. Smith said, “Don’t tell your friends their social faults; they will cure the fault and never forgive you.” (the full statement)
I agree with L.P. Smith, who simply said, “Don’t tell your friends their social faults.” (as quoted, omitting the semicolon)

Quotation marks in headlines and subheadings

Use only a single quote mark when quoted words are in a headline or subheading, not double quotation marks.

Correct: President Obama says “help will be given” in response to disaster


Use a semicolon instead of a comma when joining two sentences with a coordinate conjunction (and, but, or, nor, for, yet, so) AND when one of the sentences has one or more commas in it. The semicolon marks the break between the two sentences better than another comma would.

Use a semicolon to link two closely related sentences that show contrasts or parallels and to separate items in a series when one or more of the items require commas.

I eat chocolate pastries; she prefers fruit salad.
He went to the store to buy fruit, vegetables, and bread; clothes for his child; and a new television.
The East Coast is known for its history; the West Coast is famous for its contemporary lifestyle.

Use semicolons – instead of commas – to separate lengthy, complicated items in a series (but always if the items themselves contain commas).

The recipe calls for seven cups of fresh, finely chopped herbs; two cups of homemade red wine vinaigrette; three tablespoons of virgin olive oil; and two teaspoons of Lawry’s seasoning salt.

Spacing after punctuation

Use only one space following periods, commas, semicolons, colons, exclamation points, question marks, and quotation marks.

The student walked into the classroom. He was surprised to find he was 10 minutes late.
Are you coming to the picnic? If so, I’ll see you there.
“Have a good weekend,” she said as she hung up the phone.

There should be no space before or after an ellipsis, nor should there be spaces between the periods in an ellipsis.

Correct: This course introduces/covers/includes/provides…
Incorrect: This course introduces/covers/includes/provides . . .

When using a dash, use a double dash (en dash) with a space on either side of it. (An en dash is formed by typing two hyphens and a space. Microsoft Word will automatically make the two hyphens a solid dash.)

Incorrect: The rededication of the White Building – the first building on campus – took place in August.
Incorrect: The rededication of the White Building—the first building on campus—took place in August.
Incorrect: The rededication of the White Building-the first building on campus-took place in August.

**Note: See the bullets section for guidelines for punctuating bulleted items.