The Modern Language Association, or MLA, publishes a handbook commonly used in high schools and undergraduate humanities programs in the United States. The handbook explains the MLA style for writing research papers and the appropriate way to punctuate sentences and cite works referenced. MLA comma rules vary from the rules of other writing styles.
Commas in Quotations
MLA style calls for placing the comma inside a set of quotation marks, just before the closing quotation mark in most cases. If you are quoting someone without adding a parenthetical citation or placing a title in quotation marks, the comma goes inside the marks. If you are placing a citation at the end of the quote, the comma will go after the citation. For example: "In his famous book, Smith wrote, 'I have lived an exciting life' (45), meaning his life was fulfilling."
Commas in Citations
In MLA style, a writer must make in-text citations following a quotation. The proper way of formatting the in-text citations is to place the author's last name and the page number that the quotation is found on in parentheses after the the quote. You do not use a comma to separate the name and the page number. For example, (Smith, 123) is incorrect. The correct way is (Smith 123). If you are citing the title of a book or paper, either because there is no author or because you are using two works by the same author, you do not use a comma between the title and the page number. If you are citing a work by more than one but three or fewer authors, use a comma to separate the names in the citation: (Smith, Jones, and Miller 123).
Commas in the Works Cited List
If you cite a work in a paper, you must include the work on the list of works cited at the end of the paper. MLA has specific rules for listing works and how to punctuate the list. Use a comma to separate the author's last and first names, listing the last name first: "Smith, Jonathan." Place a period after the name, a period after the title of the work. Type the publishing company and a colon, then the city of publication. Use a comma after the city then type the date: "Harvard Books: New York, 2001." If you are citing a non-book work, such as a website or piece of visual art, list where the work can be found and the date of publication or creation, separated by a comma. For example, if you are citing a painting in a museum, write "Museum name, 1905." If there is no date given, write "n.d."
MLA style uses the serial comma, also called the Oxford comma or Harvard comma. If you are writing a list of objects or adjectives, separate each object with a comma. You also use a comma before the conjunction in MLA style. For example, if you are describing someone, write "he was tall, strange, and skinny" instead of "he was tall, strange and skinny."