Punctuation
This resource was written by Purdue OWL.
Last full revision by Morgan Sousa.
Last edited by Dana Lynn Driscoll on September 18th 2007 at 4:54PM
Summary: When speaking, we can pause or change the tone of our voices to indicate emphasis. When writing, we must use punctuation to indicate these places of emphasis. This resource should help to clarify when and how to use various marks of punctuation.
Jump to listing of all of this resource's sections
Brief Overview of Punctuation
When speaking, we can pause or change the tone of our voices to indicate
emphasis. When writing, we use punctuation to indicate these places of
emphases. This handout should help to clarify when and how to use various
marks of punctuation.
Independent clause: a clause that has a subject and a
verb and can stand alone; a complete sentence
Dependent clause: a clause that has a subject and a verb
but cannot stand alone; an incomplete sentence
Comma
Use a comma to join 2 independent clauses by a comma and a coordinating
conjunction (and, but, or, for, nor, so).
Road construction can be inconvenient, but it is
necessary.
The new house has a large fenced backyard, so I am
sure our dog will enjoy it.
Use a comma after an introductory phrase, prepositional phrase, or
dependent clause.
To get a good grade, you must complete all your
assignments.
Because Dad caught the chicken pox, we canceled our
vacation.
After the wedding, the guests attended the
reception.
Use a comma to separate elements in a series. Although there is no set
rule that requires a comma before the last item in a series, it seems to
be a general academic convention to include it. The examples below
demonstrate this trend.
On her vacation, Lisa visited Greece, Spain, and
Italy.
In their speeches, many of the candidates promised to
help protect the environment, bring about world peace, and end world
hunger.
Use a comma to separate nonessential elements from a sentence. More
specifically, when a sentence includes information that is not crucial to
the message or intent of the sentence, enclose it in or separate it by
commas.
John's truck, a red Chevrolet, needs new tires.
When he realized he had overslept, Matt rushed to his
car and hurried to work.
Use a comma between coordinate adjectives (adjectives that are equal and
reversible).
The irritable, fidgety crowd waited impatiently for
the rally speeches to begin.
The sturdy, compact suitcase made a perfect
gift.
Use a comma after a transitional element (however, therefore, nonetheless,
also, otherwise, finally, instead, thus, of course, above all, for example,
in other words, as a result, on the other hand, in conclusion, in
addition)
For example, the Red Sox, Yankees, and Indians are
popular baseball teams.
If you really want to get a good grade this semester,
however, you must complete all assignments, attend class, and study your
notes.
Use a comma with quoted words.
"Yes," she promised. Todd replied, saying, "I will be
back this afternoon."
Use a comma in a date.
October 25, 1999
Monday, October 25, 1999
25 October 1999
Use a comma in a number.
15,000,000
1614 High Street
Use a comma in a personal title.
Pam Smith, MD
Mike Rose, Chief Financial Officer for Operations,
reported the quarter's earnings.
Use a comma to separate a city name from the state.
West Lafayette, Indiana
Dallas, Texas
Avoid comma splices (two independent clauses joined only by a comma).
Instead, separate the clauses with a period, with a comma followed by a
coordinating conjunction, or with a semicolon.
Semicolon
Use a semicolon to join 2 independent clauses when the second clause
restates the first or when the two clauses are of equal emphasis.
Road construction in Dallas has hindered travel
around town; streets have become covered with bulldozers, trucks, and
cones.
Use a semicolon to join 2 independent clauses when the second clause
begins with a conjunctive adverb (however, therefore, moreover,
furthermore, thus, meanwhile, nonetheless, otherwise) or a transition (in
fact, for example, that is, for instance, in addition, in other words, on
the other hand, even so).
Terrorism in the United States has become a recent
concern; in fact, the concern for America's safety has led to an awareness
of global terrorism.
Use a semicolon to join elements of a series when individual items of the
series already include commas.
Recent sites of the Olympic Games include Athens,
Greece; Salt Lake City, Utah; Sydney, Australia; Nagano, Japan.
Colon
Use a colon to join 2 independent clauses when you wish to emphasize the
second clause.
Road construction in Dallas has hindered travel
around town: parts of Main, Fifth, and West Street are closed during the
construction.
Use a colon after an independent clause when it is followed by a list, a
quotation, appositive, or other idea directly related to the independent
clause.
Julie went to the store for some groceries: milk,
bread, coffee, and cheese.
In his Gettysburg Address, Abraham Lincoln urges
Americans to rededicate themselves to the unfinished work of the deceased
soldiers: "It is for us the living rather to be dedicated here to the
unfinished work which they who fought here have thus far so nobly
advanced. It is rather for us to be here dedicated to the great task
remaining before us — that from these honored dead we take increased
devotion to that cause for which they gave the last full measure of
devotion — that we here highly resolve that these dead shall not
have died in vain, that this nation under God shall have a new birth of
freedom, and that government of the people, by the people, for the people
shall not perish from the earth."
I know the perfect job for her: a politician.
Use a colon at the end of a business letter greeting.
To Whom It May Concern:
Use a colon to separate the hour and minute(s) in a time notation.
12:00 p.m.
Use a colon to separate the chapter and verse in a Biblical reference.
Matthew 1:6
Parenthesis
Parentheses are used to emphasize content. They place more emphasis on the
enclosed content than commas. Use parentheses to set off nonessential
material, such as dates, clarifying information, or sources, from a
sentence.
Muhammed Ali (1942-present), arguably the greatest
athlete of all time, claimed he would "float like a butterfly, sting like
a bee."
Dash
Dashes are used to set off or emphasize the content enclosed within dashes
or the content that follows a dash. Dashes place more emphasis on this
content than parentheses.
Perhaps one reason why the term has been so
problematic—so resistant to definition, and yet so transitory in
those definitions—is because of its multitude of
applications.
In terms of public legitimacy—that is, in terms
of garnering support from state legislators, parents, donors, and
university administrators—English departments are primarily places
where advanced literacy is taught.
The U.S.S. Constitution became known as "Old
Ironsides" during the War of 1812—during which the cannonballs fired
from the British H.M.S. Guerriere merely bounced off the sides of the
Constitution.
To some of you, my proposals may seem
radical—even revolutionary.
Use a dash to set off an appositive phrase that already includes commas.
An appositive is a word that adds explanatory or clarifying information to
the noun that precedes it.
The cousins—Tina, Todd, and Sam—arrived
at the party together.
Quotation Marks
Use quotation marks to enclose direct quotations. Note that commas and
periods are placed inside the closing quotation mark, and colons and
semicolons are placed outside. The placement of question and exclamation
marks depends on the situation.
He asked, "When will you be arriving?" I answered,
"Sometime after 6:30."
Use quotation marks to indicate the novel, ironic, or reserved use of a
word.
History is stained with blood spilled in the name of
"justice."
Use quotation marks around the titles of short poems, song titles, short
stories, magazine or newspaper articles, essays, speeches, chapter titles,
short films, and episodes of television or radio shows.
"Self-Reliance," by Ralph Waldo Emerson
"Just Like a Woman," by Bob Dylan
"The Smelly Car," an episode of Seinfeld
Do not use quotation marks in indirect or block quotations.
Italics
Underlining and Italics are often used interchangeably. Before
word-processing programs were widely available, writers would underline
certain words to indicate to publishers to italicize whatever was
underlined. Although the general trend has been moving toward italicizing
instead of underlining, you should remain consistent with your choice
throughout your paper. To be safe, you could check with your teacher to
find out which he/she prefers.
Italicize the titles of magazines, books, newspapers, academic journals,
films, television shows, long poems, plays of three or more acts, operas,
musical albums, works of art, websites, and individual trains, planes, or
ships.
Time
Romeo and Juliet by William
Shakespeare
The Metamorphosis of Narcissus by Salvador
Dali
Amazon.com
Titanic
Italicize foreign words.
Semper fi, the motto of the U.S. Marine
Corps, means "always faithful."
Italicize a word or phrase to add emphasis.
The truth is of utmost concern!
Italicize a word when referring to that word.
The word justice is often misunderstood and
therefore misused.