When to Use ‘et al.’ in Citations and How to Format It Correctly

In the realm of academic writing, clarity, accuracy, and consistency in citation are essential. Among the many citation conventions used in scholarly communication, et al. stands out as one of the most common—and commonly misused. Derived from the Latin phrase et alia, meaning “and others,” this abbreviation is indispensable for managing citations involving multiple authors. Understanding when to use et al., how to format it across different citation styles, and how to avoid common mistakes with et al. is crucial for both novice writers and seasoned researchers.

This article explores the proper use of et al. in major citation styles, including APA 7th edition, MLA 9th edition, and Chicago style. Along the way, it highlights nuances in et al. punctuation rules, addresses whether et al. should be italicized or not, and explains the difference between et al. in APA vs MLA. With a balanced focus on technical accuracy and accessibility, this guide aims to strengthen your citation practices and reduce formatting errors.

What Does et al. Mean in Research?

In research contexts, et al. is a convenient abbreviation used to reference a work by multiple authors without having to list each one. This abbreviation streamlines in-text citations and reference entries, preventing disruptions in the narrative flow of academic texts. For instance, rather than writing out all five authors of a source, you can write:

Smith et al. (2021) argue that...

This shorthand enhances readability and ensures consistency, especially in disciplines where sources often have lengthy author lists. However, while the principle is straightforward, its execution varies significantly depending on the citation style you're using.

How to Use et al. in Citations?

Citation styles have specific guidelines for using et al., and these differences can lead to confusion. A deep understanding of these style-specific rules ensures accurate representation of sources and strengthens the integrity of your work.

APA 7th Edition et al.

In APA 7th edition, et al. is used for in-text citations when a work has three or more authors. This rule applies universally across all in-text references.

Example:

(Garcia et al., 2020)

However, in the reference list, APA now requires listing up to 20 authors before using an ellipsis followed by the final author’s name. This change from earlier editions emphasizes transparency while still maintaining readability.

Crucially, APA style does not italicize et al., and a period follows "al." since it is an abbreviation. A frequent citation error in APA is inserting a comma between the author’s name and et al., which is incorrect.

MLA 9th Edition Citation Rules

The MLA 9th edition adopts a similar approach but with some notable distinctions. In MLA style, et al. is used for three or more authors in both in-text citations and the Works Cited list.

In-text:

(Lopez et al. 57)

Works Cited:

Lopez, Maria, et al. Understanding Global Inequality. Oxford UP, 2021.

Unlike APA, MLA italicizes et al. in the Works Cited section as part of its convention to treat Latin phrases as foreign terms. However, in in-text citations, italicization is optional and often omitted in practice. This flexible approach to formatting creates a key difference between et al. in APA vs MLA, underlining the importance of consulting the appropriate style manual.

et al. in Chicago Style

Chicago style, which offers both the Author-Date and Notes and Bibliography systems, provides flexible rules for et al. usage. Typically, et al. is used for four or more authors in in-text citations or footnotes.

Author-Date:

(Nguyen et al. 2022)

Notes and Bibliography:

Minh Nguyen et al., Economic Transitions in Asia (Cambridge University Press, 2022).

As in APA, et al. is not italicized and is always followed by a period. Chicago style may use slightly different punctuation in bibliographic entries compared to in-text citations or footnotes, which can sometimes lead to inconsistencies if writers are not careful.

Comparative Table: et al. Usage Across Citation Styles

To make these distinctions clearer, the following table offers a side-by-side comparison of how et al. is used in APA, MLA, and Chicago styles:

Feature	APA 7th Edition	MLA 9th Edition	Chicago Style (17th Ed.)
When to use et al. in-text	3 or more authors	3 or more authors	4 or more authors
When to use et al. in references	Never (list up to 20 authors)	Yes, for 3+ authors in Works Cited	Yes, depending on version (NB or Author-Date)
Italicized or not	Not italicized	Italicized in Works Cited (not in-text)	Not italicized
Comma before et al.?	No (e.g., Smith et al.)	Yes, in Works Cited (e.g., Smith, et al.)	Optional based on structure
Period after “al”	Yes (et al.)	Yes (et al.)	Yes (et al.)
Used in bibliography?	No, full author list up to 20	Yes	Yes
Font style	Regular	Italic (sometimes)	Regular
Example in-text citation	(Garcia et al., 2020)	(Lopez et al. 57)	(Nguyen et al. 2022)
Example reference entry	Garcia, M., Lopez, A., Zhang, K., & Hughes, B. (2020)...	Lopez, Maria, et al. Understanding Global Inequality...	Nguyen, Minh, et al. Economic Transitions in Asia...

This table serves as a practical reference tool, helping writers ensure they’re not misapplying et al. conventions based on assumptions from a different style guide.

Common Mistakes with et al.

Despite its apparent simplicity, et al. is prone to a number of common formatting errors:

Incorrect punctuation, such as omitting the period after "al."
Misplaced commas, especially in APA style where no comma should appear before et al.
Inconsistent italicization, particularly in MLA where italicization applies selectively.
Overuse in reference lists, even when full author names are required.

These seemingly small errors can lead to negative evaluations in academic settings, reduce the credibility of manuscripts, or cause confusion for readers attempting to locate sources.

Why It Matters: The Practical Implications of Correct Citation

Correctly applying the et al. citation rules is more than a formality. It's a reflection of scholarly rigor and attention to detail. Misused citations may result in ambiguous attribution, disrupting the reader’s understanding of your sources. Worse still, repeated citation mistakes can raise concerns about plagiarism or lack of academic professionalism.

Given the intricacies of different citation styles, many scholars turn to editing services to ensure their writing adheres to every detail—especially when preparing documents for publication or evaluation.

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If you’re uncertain about the nuances of how to use et al. in citations, let the experts help. At PaperEdit.com, we specialize in academic editing for theses, dissertations, journal articles, and research papers. Our professional editors are fluent in APA, MLA, Chicago, and other major citation formats.

We not only correct formatting issues, but we also review your document for clarity, consistency, and academic tone—ensuring you meet the highest scholarly standards. Whether you're preparing a PhD thesis or submitting to an academic journal, our team ensures your citations are polished, precise, and professionally formatted.

Conclusion

In conclusion, understanding when to use et al., how to format it correctly, and what pitfalls to avoid is essential for effective academic communication. Each citation style—APA 7th edition, MLA 9th edition, and Chicago style—has its own approach to et al., affecting everything from punctuation to italicization. By consulting style guides, using reliable examples, and referring to tools like the comparison table above, writers can confidently navigate the complexities of academic citation.

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