| Using Colons
Correctly
Some uses of the colon are purely conventional--after
the greeting in business letters (Dear Mr. Johnson:), between
the hour and minute in expressions of time (2:30 a.m.), between
a title and subtitle (George
Washington: A Man of His Time), and between book and verse numbers
in biblical citations (I Corinthians:2-5)—and those
uses will not be discussed in this handout. But other uses of the
colon have a grammatical
purpose, and since those uses are the ones that are most often misunderstood,
they are the ones we will consider.
Colons (:) can be used as sentence connectors in several ways: to
introduce lists or series, including bulleted lists; to introduce
quotations, including block quotations; and, in special circumstances,
to join two sentences to create a compound sentence.
The main rule for correctly punctuating with colons is to
make sure that what comes before the colon is a complete grammatical
construction
(usually a complete sentence). To test whether you have used a colon
correctly or incorrectly, delete the information after the colon
to see if what is left is a sentence that can stand alone. If the
information does stand alone, then you have used the colon correctly.
If the information that comes before the colon cannot stand alone,
then you shouldn’t use a colon there.
Let’s look at a sentence that uses the colon correctly.
Ex.: Three things are most important for a five-year-old child:
Mommy Daddy, and home.
In this sentence, when we delete the information after the colon (Mommy, Daddy,
and home), we are left with a clause that could be a complete sentence (Three
things are most important for a five-year-old child). We could put a period
after child, and everyone would understand the statement as a sentence.
Now let’s look at a sentence that uses the colon incorrectly.
Ex.: The three most important things for a five-year-old child are:
Mommy, Daddy, and home.
In this example, when we delete the information after the colon (Mommy,
Daddy, and home.) we see that what is left (The three most
important things for a five-year-old are) cannot stand alone; we could not put
a period after are, so we should not use a colon there.
Using Colons to Introduce Series and Lists
We often use colons to set up lists or series of items when we want
to emphasize the list or series for some reason. We use the colon
in such cases to point to the information that comes after it. Most
often the list is an appositive that renames or defines some part
of the information that comes before the colon, and the information
can be presented as either a horizontal list or as a vertical list.
But the main rule for using colons still applies: the information
that comes before the colon must be a complete sentence.
Let’s look at an example.
Ex.: Susan plans on bringing several crucial items to the picnic: cokes, napkins,
plates and forks.
In the example above, the horizontal list following the
colon is an appositive that more specifically defines
the items that Susan
will bring to the picnic.
Please note that we could put a period after picnic, and the sentence
would still make sense.
Now let’s look at the same information in a sentence that is
punctuated incorrectly.
Ex.: Susan plans on bringing: cokes, napkins, forks and plates.
The example above illustrates an incorrect use of the colon. If the
list is deleted, the sentence no longer makes sense and the remaining
information (Susan plans on bringing) is a fragment.
The same rule applies when you use colons to set up vertical lists,
including numbered or bulleted lists: the information before
the colon must be a complete sentence.
Ex.: The AMA has identified
four major symptoms of drug abuse:
- Red eyes,
- Problems with comprehension,
- Withdrawal from social interaction,
and
- Depression.
(Please note that capitalizing the first word
in each item of a bulleted list is optional—though capitalizing
perhaps provides more emphasis. Also note that the comma between
items is considered
optional in most business and technical writing.)
Using Colons to Introduce Quotations
If you haven’t already noticed the pattern, let me say again,
when you use a colon to introduce a quotation, the information
that comes before the colon must be a complete sentence.
Ex.: Frederick expresses his concern about heart disease: “Deaths
from heart disease in America will increase five-fold in the next twenty
years.”
Here’s a hint about introducing a quotation with a sentence
and a colon: the information before the colon should add to the reader’s
understanding of the quotation—it should set up a context for
or explain something about the quote. This hint becomes even more
important when you are setting up a block quotation.
Ex.: In The Power of Myth, a conversation about mythology, Joseph
Campbell enlightens Bill Moyers about how a dream differs from
a myth: “Oh,
because a dream is a personal experience of that deep, dark ground
that is the
support of our conscious lives, and a myth is society’s
dream" (40).
Using Colons to Create Compound Sentences
We all know that we can use a semicolon to join two sentences to
create a compound sentence when the two sentences are closely related.
But when the first sentence of the pair creates an expectation in
the reader that the second sentence fulfills, then the correct punctuation
to use to connect them is a colon. In other words the second sentence
illustrates, explains or exemplifies the idea expressed in the first
sentence.
Ex.: The adoption of a totem implies an awareness of a disunity where there
once was unity: the conscious human decision to adopt the totem must have arisen
from a sense of loss or absence and the desire to bridge the chasm.
Please note, you have the option of capitalizing the first word after the
colon in this kind of compound sentence.
You can test your understanding of this handout by completing Academic
Center exercises available here.
|
