To quote a passage from a source:

1.  Enclose all quoted material within quotation marks. Make sure you have copied the original accurately.

To punctuate quotations, remember this simple rule: periods and commas always go inside quotation marks. Place semicolons and colons outside quotation marks. Place a question mark or exclamation point inside quotation marks only when the quotation itself is a direct question or exclamation. If it is not, place these marks outside.

Fit your quotation logically and grammatically into your sentence. The punctuation your sentence requires takes precedence over the punctuation of the original quotation.

Thoreau asks, "Why should we live with such hurry and waste of life?" (63).

Why does Thoreau insist that "we live with such hurry and waste of life"(63)?

Thoreau asserted that he "wished to live deliberately"; however, he often seemed to act impulsively (61).
 

2.  Introduce each quotation with a "signal phrase." Often this phrase will include the author's name and/or title of the work.

3.  Accordiing to the MLA format, you should cite each quotation parenthetically at its end, either by author and page number or simply by page number (depending on whether the author's name appears in the "signal phrase."

Although he insists he wants "to live deliberately," he often acts impulsively (Thoreau 61).

Thoreau asserted that he "wished to live deliberately"; however, he often seemed to act impulsively (61).

4.  If any quotation is longer than four typed lines, block it to set it off from the rest of the text: indent it 10 spaces from the left margin; keep the normal right hand margin; and double space.
 

5.  Use a colon to incorporate the quotation into your paragraph when the statement which preceded it is a sentence in its own right.

Thoreau's explanation of why he went to live at Walden reveals his idealism:

I went to the woods because I wished to live deliberately , to front only the essential facts of life, and see if I could not learn what it had to teach, and not, when I came to die, discover that I had not lived. I did not wish to live what was not life, living is so dear; nor did I wish to practice resignation, unless it was quite necessary. (61)

6.  Use an ellipsis (three spaced dots) to show that you have omitted something in a quotation.

Thoreau explains that he went to live at Walden because he "wished to live deliberately . . . to live deep and suck out all the marrow of life" (61).

7.  If it is necessary to change the tense of a verb or substitute a proper name for a pronoun in a quotation for the sake of clarity or coherence, use brackets to enclose the material you are inserting.

Thoreau does not want to find when he dies "that [he has] not lived" (61).

8.  If you are quoting fewer than four lines of poetry, include it in your text. Separate the lines with virgules with a space before and after ( / ).

In her long poem "Transcendental Etude," Adrienne Rich describes a new kind of poetry, one which "has nothing to do with eternity, / the striving for greatness, brilliance-- / only with the musing of a mind . . . "; she envisions the creator of this poetry as a woman carefully piecing together scraps of material: "pulling the tenets of her life together / with no mere will to mastery."

9.  When quoting more than four lines of poetry, double-space it and indent it ten spaces from the left margin. Make sure you retain the original line breaks as well as features such as spacing, punctuation, capitalization, and indentation. Do not use quotation marks for block quotations.

In "Transcendental Etude," Adrienne Rich skillfully develops an analogy between practicing music and practicing life:

 
No one  ever told us we had to study our lives,
make of our lives a study, as if learning natural history
or music, that we should begin with the simple exercises first
and slowly go on trying
the hard ones, practicing till strength
and accuracy become one with the daring
to leap into transcendence, take the chance
of breaking down in the wild arpeggio
or faulting the full sentence of the fugue.
--And in fact we can't live like that . . .

10.  If you cut out a line or more of poetry in a block quote, represent this "missing chunk" with a line of ellipses.

11.  Cite line numbers whenever possible.

Universes round the Mundane Egg remains Chaotic:
One to the North, named Urthona:  One to the South, named
Urizen:
.................................................................
And Albion was slain upon his mountains, & in his tent;
All fell towards the Centre in dire ruin, sinking down.  ("Milton" 18:15-22)

Blake scholars have often questioned, as does Urizen in "Jerusalem: The Emanation of the Giant Albion," "O Dkofield, why art thou / cruel?" (68:2-3)

12.  When reproducing dialogue in drama, set quotations off from the text. Begin each character's speach with the character's name at left margin in capitals, followed by a period and the quotation and indent all subsequent lines about a quarter inch.

Moliere's depiction of Orgon as an utter fool is balanced by his Cleante's as a crafty woman:

 
ORGON:  Maybe he's coming to patch the business up.
               How do you think I ought to act to him?
CLEANTE:  You musn't show how deeply you're offended;
                   And if he offers peace, you'd better heed him.
                   ("Tartuffe" 213)