Introducing Quotations

Quotations and paraphrases should almost always be introduced by a phrase or even a whole sentence. This "signal phrase," as one grammarian calls it, often names the author and serves to blend what is quoted or paraphrased into your own argument, the flow and development of your own ideas. Virtually never should a quotation appear as a separate sentence in your paper, unaccompanied by some introductory, or sometimes trailing phrase. The exception is when the quotation is used as an epigram, which by definition appears out of nowhere at the start of an essay or section of an essay. Punctuate these introductory phrases or sentences as follows:

bulletIf using a phrase to introduce, punctuate with a comma:
As the United States Catholic Bishops Conference asserts, "Catholics in the United States have special responsibilities to protect human life and dignity and to stand with those who are poor and vulnerable" (Everyday).

            or

bulletThe United States Catholic Bishops Conference's 1998 document, Everyday Christianity: To Hunger and Thirst for Justice, asserts, "Catholics in the United States have special responsibilities to protect human life and dignity and to stand with those who are poor and vulnerable."
bulletIf using a whole sentence as an introduction, end it with a colon:
But the Bishops deny that political opinions are simply a private matter: "Our political choices should not reflect simply our own interests, partisan preferences or ideological agendas, but should be shaped by the principles of our faith and our commitment to justice, especially to the weak and vulnerable" (USCC, Everyday).
bulletFinally, it is possible just to blend your sentence right into the quotation with no punctuation:
The US Catholic Conference repudiates the contention "that religion is a private matter, to be tolerated as long as it is detached from our lives as workers and citizens" (Everyday).
or:
Everyday Christianity: To Hunger and Thirst for Justice by the US Catholic Conference repudiates the contention "that religion is a private matter, to be tolerated as long as it is detached from our lives as workers and citizens."

 

bullet"Everyday" here refers to a specific publication of the US Catholic Bishops Conference (NCCB).  It is listed in the Works Cited thus:

National Conference of Catholic Bishops. Everyday Christianity: To Hunger and Thirst for Justice. Washington, DC: USCC, 1998. Web. 12 May 2001.

Verbs to use in Introducing Quotations*: (This list is not exhaustive, but is a good start.)

acknowledges
adds
admits
agrees
argues
asserts
believes
claims
comments
compares
confirms
contends
declares
denies
disputes
emphasizes
endorses
grants
illustrates
implies
insists
notes
observes
points out
reasons
refutes
rejects
reports
responds
suggests
thinks
writes

*This list comes from Diana Hacker, A Writer's Reference 4th ed. © 1999 Bedford/St. Martins.