What et al. means and when to use it in APA and MLA

“Et al.” is a Latin abbreviation of et alii, which means “and others.” Citation styles use it to shorten a long list of authors to the first author’s name. Where it appears, and from how many authors it applies, depends on the style and on whether you are writing an in-text citation, a reference entry, or a sentence of your own.

The two most common rules are simple to state. APA 7 uses “et al.” in the text for three or more authors and names every author in the reference list. MLA 9 uses it for three or more authors in the text and in the Works Cited list, but not in your own sentences. The details below are what trips people up.

How to write it

Write “et al.” with a period after “al” and no period after “et.” The period belongs to the abbreviation of alii. “Et. al.” is a common mistake.

In MLA citations, “et al.” is set in ordinary roman type. MLA says to italicize it only when you are talking about the term itself, as in a sentence about what et al. means. MLA’s examples show a comma before it in a Works Cited entry, “Burdick, Anne, et al.”, and no comma in a parenthetical citation, “(Burdick et al. 42).”

APA 7

In the text

APA uses author and year. For one or two authors, you name every author in every citation. For three or more, you give the first author’s name and “et al.” in every citation, including the first one.

• Parenthetical: (Martin et al., 2020)
• Narrative: Martin et al. (2020) found that…

The seventh edition shortens a work with three or more authors immediately, even on first mention. APA’s own blog says this also reduces how often a researcher’s name appears in a paper.

There is one exception. If two works in your paper would shorten to the same “et al.” form, spell out as many surnames as you need to tell them apart. Say one paper is by Martin, Chen and Okoye (2020) and another is by Martin, Chen and Nair (2020). Both would shorten to (Martin et al., 2020), so you would write (Martin, Chen, & Okoye, 2020) and (Martin, Chen, & Nair, 2020).

In the reference list

The reference list does not use “et al.” for most sources. APA says to include every author for a source with up to 20 authors. For a source with 21 or more, you list the first 19 authors, then an ellipsis, then the final author.

APA changed this in the seventh edition. Its stated reasons are that most references now need no ellipsis at all, which removes a rule people found hard to remember, and that more authors get their names credited in the list.

MLA 9

In the text

For a work with three or more authors, a parenthetical citation gives the first author’s surname followed by “et al.” and the page number, with no comma: (Burdick et al. 42). For two authors, name both and join them with “and.”

In your own sentences, MLA asks you to leave “et al.” out. The MLA Style Center says to spell out the authors’ names, or to give the first author’s name followed by “and others,” and to reserve “et al.” for parenthetical citations and the Works Cited list. So you would write “Burdick and others argue that…” and cite the page in parentheses.

In the Works Cited list

When a source has three or more authors, MLA gives only the first author, followed by “et al.” The MLA Style Center’s 2022 article on the ninth edition shows the pattern in a journal entry: “Adams, Peter, et al.” The comma after the author’s first name is part of the pattern.

The same lead author with different coauthors

MLA’s usual shortcut for several works by one author, three hyphens in place of the name, does not work here. The MLA Style Center says that if the same lead author appears with different coauthors, each entry must repeat the lead author’s name and “et al.” In the text, a shortened form of the title tells the entries apart. The MLA Style Center’s examples give a title in quotation marks after “Taylor et al.”, and it notes that the ninth edition updates the guidance, so check the Handbook for the exact punctuation your instructor expects.

Side by side

Mistakes to avoid

• Writing “et. al.” or “et al” without the period. The correct form is “et al.”
• Using “et al.” for two authors. APA names both authors every time, and MLA joins them with “and.”
• Using “et al.” in an APA reference list for a source with 3 to 20 authors. APA lists every author there.
• Using “et al.” in your own MLA sentence. MLA reserves it for parenthetical citations and the Works Cited list.
• Naming every author in an MLA Works Cited entry for a source with three or more. MLA gives the first author and “et al.”
• Shortening two different sources to the same “et al.” in APA. Spell out names until the citations differ.
• Italicizing “et al.” in an MLA citation. MLA sets it in roman type.

Other styles

Other styles set their own thresholds. Chicago, for example, does not use the same cut-offs as APA or MLA. When you switch styles, do not carry over the rule you learned for the last one. The glossary entry for et al. summarizes the thresholds, and each guide for a source type shows the pattern for its style.

Letting a tool handle it

PaperCitation’s APA and MLA generators apply each style’s rule when they build an entry. For example, the MLA entry for the three-author 2015 Nature paper “Deep learning” begins “LeCun, Yann, et al.”, while the APA entry names all three authors. Compare what a tool gives you with your instructor’s examples, since small differences in author lists are easy to miss.

The reference checker can also confirm that the sources in a finished list exist and that their authors, year and journal match the published record. The post on how to cite sources in a paper shows where each kind of citation goes.