“Et al.” is short for the Latin phrase et alia, meaning “and others.” You use it to shorten citations when a source has multiple authors, replacing every name after the first. The exact rules depend on which style guide you’re following, but the core idea is the same: list the first author’s last name, add “et al.,” and move on. Here’s how it works in the two most common academic styles, plus the formatting details that trip people up.
How to Use Et Al. in APA Style
APA style (7th edition) has a simple, consistent rule: for any work with three or more authors, use only the first author’s last name followed by “et al.” in every in-text citation, including the very first one. You never need to list all the authors in the body of your paper, no matter how many there are.
A parenthetical citation looks like this:
- (Taylor et al., 2022)
A narrative citation, where the author’s name is part of your sentence, looks like this:
- Taylor et al. (2022) found that…
For works with just one or two authors, spell out every name every time. Et al. only kicks in at three or more.
In your reference list at the end of the paper, the rules are different. List up to 20 authors by name before using an ellipsis and the final author’s name. Et al. is not used in the APA reference list itself.
How to Use Et Al. in MLA Style
MLA (9th edition) uses the same threshold: three or more authors. When a source has three or more authors, list only the first author’s last name followed by “et al.” in both your in-text citation and your Works Cited entry.
An in-text citation looks like this:
- (Nickels et al. 85)
Notice there’s no comma between “et al.” and the page number in MLA, unlike APA where a comma separates “et al.” from the year.
In the Works Cited list, the entry starts with the first author’s full name (last name first), followed by “et al.”:
- Nickels, William, et al. Understanding Business. 9th ed., McGraw-Hill Ryerson, 2016.
This is a key difference from APA. MLA uses et al. in the bibliography, while APA spells out author names in the reference list.
How to Use Et Al. in Chicago Style
Chicago style follows a similar pattern but with slightly different mechanics depending on whether you’re using notes-bibliography or author-date format. In the author-date system, use et al. for works with four or more authors in your in-text citations. In footnotes, list all authors in the first note (up to three), and shorten to the first author plus et al. in subsequent notes. In the bibliography, list up to 10 authors before switching to et al.
Punctuation and Formatting
A few small details matter more than you’d think, because getting them wrong can cost you points on a paper.
The period after “al.”: “Al.” is an abbreviation, so it always has a period. “Et” is a complete Latin word, not an abbreviation, so it never gets one. The correct form is “et al.” with only one period. If et al. falls at the end of a sentence, you don’t add a second period.
Italics: Do not italicize et al. in your citations or bibliography entries. According to the MLA Style Center, you only italicize “et al.” when you’re discussing it as a term (the way this article does). In actual citations and Works Cited entries, it stays in regular (roman) type. The same convention holds in APA.
Comma placement: In APA, a comma comes before et al. only when you would normally have one in the author list. For a work with three or more authors, you jump straight from the first author to et al. with no comma: (Rivera et al., 2023). The comma you see is between “et al.” and the year, not before “et al.” In MLA, there’s no comma at all in the parenthetical citation because MLA doesn’t use commas between author and page number: (Rivera et al. 47).
When Two Sources Shorten to the Same Citation
Sometimes you’ll cite two different sources that have the same first author and publication year. When both get shortened to et al., your reader can’t tell them apart. Each style handles this a little differently.
In APA, if the shortened forms would be identical, add enough additional author names to distinguish them. For example, if you’re citing both a 2021 paper by Smith, Jones, and Lee and a 2021 paper by Smith, Park, and Chen, you’d write (Smith, Jones, et al., 2021) and (Smith, Park, et al., 2021). If the author lists are truly identical but the works are different, APA uses lowercase letters after the year: (Smith et al., 2021a) and (Smith et al., 2021b). Those letters are assigned based on alphabetical order of the titles in your reference list.
In MLA, you’d similarly include enough author names to make the citations distinct, or add a shortened title to clarify which work you mean.
Quick Reference by Style
- APA (7th edition): Use et al. for 3+ authors in every in-text citation. Spell out authors in the reference list.
- MLA (9th edition): Use et al. for 3+ authors in both in-text citations and Works Cited entries.
- Chicago: Use et al. for 4+ authors in author-date citations. Rules vary for footnotes and bibliography.
Whichever style you’re using, check whether et al. belongs in your bibliography or just in the body of your paper. That’s the detail most students miss, and it’s the one most likely to differ between formats.