What et al. Means and When to Use It
et al. is a Latin abbreviation of et alii, meaning "and others." In academic writing, it allows you to condense citations when a source has three or more authors. Use et al. in in-text citations and reference lists to improve readability without omitting attribution. For the first citation, many styles require listing all authors; subsequent citations can use et al. The term is appropriate whenever a work has multiple authors and space or concision requires shortening. The abbreviation always includes a period after "al" and is typically italicized (et al.).
APA Style Rules for et al.
First In-Text Citation
In APA 7th edition, list all authors for the first in-text citation when there are three or more authors. For example: (Chen, Marks, Li, et al., 2023). In the reference list, include all authors up to 20; beyond 20, use an ellipsis followed by the final author name.
Subsequent In-Text Citations
For subsequent citations, use et al. after the first author’s surname: (Chen et al., 2023). This applies to parenthetical citations and any narrative citation where brevity is preferred. In the reference list, follow the standard formatting rules for up to 20 authors, or use an ellipsis between the 19th and last author when there are more than 20.
MLA Style Rules for et al.
In-Text Citations
MLA recommends using et al. in in-text citations for works with three or more authors. The first author’s last name is followed by et al. and no period before et: (Chen et al. 45). The Works Cited entry lists all authors up to nine; for ten or more, list the first nine, then an ellipsis. This keeps references concise while preserving credit.
Chicago Style Rules for et al.
Notes and Bibliography
In Chicago Notes and Bibliography, give the full list of authors (up to ten) in the first citation; for subsequent citations, use et al. For bibliographic entries, list the first 15 authors; if there are more, list the first 15, then a comma, and et al. In author-date, use et al. for citations with four or more authors from the first reference onward.
Best Practices and Common Pitfalls
Always defer to your style guide’s specific rule set, as conventions can differ across publishers. Use et al. to enhance clarity and reduce clutter, but ensure the first author is always clear from the context. Avoid using et al. in the first citation when your style requires full author listing, and never omit necessary attribution. In dense literature reviews, consider paraphrasing the full author list for key sources on initial mention, then using et al. thereafter.
Comparison of et al. Rules at a Glance
| Style | First In-Text Citation | Subsequent In-Text Citation | Reference List Threshold |
|---|---|---|---|
| APA | List all authors (up to 20) | First author + et al. | List up to 20; 21+ use ellipsis |
| MLA | First author + et al. | First author + et al. | Works Cited: list up to 9, then ellipsis |
| Chicago (Notes & Bib) | Full author list (up to 10) | First author + et al. | Bibliography: list up to 15, then et al. |
Frequently Asked Questions
- Should I use et al. in the reference list for a paper with 5 authors? Typically, no. In APA and MLA, you list all authors in the reference list unless the count exceeds the threshold (20 for APA, 9 for MLA). Chicago may use et al. in the bibliography after the threshold is met.
- Can et al. be used in the author position of a citation manager? Yes, but verify the output against your target style. Many reference managers allow you to set the threshold for when et al. appears in citations and references.
- Is it acceptable to cite a source with et al. in the first mention in a thesis? Follow your institution’s style guide. Many theses require full author lists on first citation, then permit et al. subsequently.
- Do I italicize et al. when using it in running text? In most style guides, et al. is italicized because it is a Latin abbreviation (et al.). Always confirm with the specific formatting rules of your chosen style.