What does et al. mean and how to use it

You are writing your first research paper and you keep seeing the same abbreviation in citations: et al. It appears after an author's name, cuts off the rest of the list, and somehow everyone seems to accept it as perfectly normal. Understanding what et al. means and how to use it correctly is not optional for serious researchers. It is a foundational citation skill that signals whether you know how academic writing actually works.

The Literal Meaning of Et Al.

Et al. is a Latin abbreviation for et alii, which translates directly to "and others." In academic writing, it serves one purpose: to shorten a citation when a source has multiple authors. Instead of listing every name in a long author group, you write the first author's surname followed by et al. The abbreviation does the rest of the work.

The phrase has been in scholarly use for centuries. It belongs to the same family of Latin abbreviations as e.g. (for example) and i.e. (that is). Unlike those two, et al. is used exclusively for people, not items or concepts. You would never write "the study examined climate, biodiversity, et al." That is a misuse. The abbreviation applies only to lists of authors or contributors.

One small but important formatting note: the period after "al" is not optional. The word et is complete on its own and needs no period, but al. is a truncation of alii, so the period is grammatically required. Omitting it is a visible error to any editor or peer reviewer.

Why Et Al. Exists in the First Place

Modern research is increasingly collaborative. A single paper in a high-impact journal might carry the names of eight, twelve, or even thirty authors. Listing every name in every in-text citation would make your prose unreadable. Et al. solves that problem cleanly. It keeps the citation informative (you still know who led the research) without burying the reader in names.

There is also a fairness dimension to the convention. The author listed before et al. is typically the first author, who usually contributed most substantially or led the project. The abbreviation acknowledges that more contributors exist without erasing them entirely. In your reference list, every author's name appears in full. Et al. is a shorthand for the body of the text, not a permanent omission.

How to Use Et Al. Across Citation Styles

The rules for when to start using et al. differ depending on which citation style your journal, teacher, or institution requires. Getting this wrong is a common mistake, and it matters. Here is how the major styles handle it.

APA Style (7th Edition)

In APA 7th edition, the threshold is simple: any work with three or more authors gets et al. from the very first citation. You write the first author's surname, followed by et al., followed by the year. For example: (Garcia et al., 2021). There is no longer a rule requiring you to list all authors the first time and abbreviate only on subsequent mentions. That rule existed in earlier editions but was removed to simplify the process.

In your reference list, APA requires you to list up to twenty authors by name. If a work has twenty-one or more authors, you list the first nineteen, insert an ellipsis, and then add the final author's name. Et al. does not appear in APA reference lists at all.

MLA Style (9th Edition)

MLA takes a different approach. For in-text citations, MLA uses the author-page format rather than author-year. When a source has three or more authors, you write the first author's name followed by et al. and the page number: (Nakamura et al. 47). In your Works Cited list, MLA instructs you to list the first author's name inverted, followed by et al., when there are three or more authors. Unlike APA, MLA does use et al. in the bibliography itself.

Chicago Style

Chicago style operates in two modes: notes-bibliography and author-date. In author-date Chicago, the rules closely mirror APA: use et al. for works with four or more authors in in-text citations. In footnotes and endnotes under the notes-bibliography system, you typically list up to three authors and then add et al. for any work with four or more. Always verify with your specific style guide edition, because Chicago has nuances that vary by discipline.

Vancouver Style

Vancouver style is common in medicine and life sciences. It uses numbered citations rather than author-name citations. When a source appears in your reference list, Vancouver traditionally lists the first six authors by name and then adds et al. if there are more. The exact threshold can vary by journal, so always check the specific publication's author guidelines.

Common Mistakes Students Make with Et Al.

Even students who understand what et al. means and how to use it still make predictable errors. Catching these before submission matters, especially if you are submitting to a peer-reviewed journal where formatting precision signals research maturity.

Using Et Al. for Two-Author Works

No major citation style permits et al. for a work with only two authors. You always write both names. Writing "Smith et al. (2020)" when the paper has only two authors is incorrect regardless of the style you are using. Both names must appear every time.

Italicizing When You Should Not

Whether to italicize et al. depends on the style guide. APA does not italicize it. MLA does not italicize it. Chicago generally does not either. Some older academic texts italicized Latin abbreviations as a matter of convention, but current standards for the major citation styles treat et al. as a fully naturalized English phrase that requires no special formatting. When in doubt, do not italicize.

Forgetting the Period

As noted earlier, the period after al. is required. A second period issue arises at the end of a sentence. If your sentence ends with a citation that includes et al., you do not add a second period. The period after al. serves double duty. Write: "This finding has been replicated across multiple studies (Garcia et al., 2021)." Not: "...studies (Garcia et al., 2021).."

Using Et Al. in Your Reference List When the Style Prohibits It

APA 7th edition is explicit: et al. does not belong in your reference list (except in the special case of twenty-one or more authors, where an ellipsis is used instead). Every author must be named in the reference entry up to the style's stated limit. Students who abbreviate their reference lists with et al. out of convenience are making a formatting error that peer reviewers and editors will flag immediately.

Et Al. in the Context of Peer-Reviewed Research

If you are submitting original research to a peer-reviewed journal, citation formatting is not a minor detail. Reviewers evaluate your work on multiple dimensions, and consistent, accurate citation practice signals that you understand the scholarly conventions of your field. To understand more about what peer review actually evaluates, read our post on what peer review actually verifies and what it does not. Citation errors do not disqualify a paper, but they create friction that a clean manuscript avoids entirely.

When you cite sources correctly, including the proper use of et al., you are also giving appropriate credit to the research community whose work supports your own. That is not a bureaucratic formality. It is a core principle of academic integrity. Every author listed in a multi-author study contributed to the knowledge you are building on. Et al. acknowledges that reality without requiring you to interrupt your argument with a list of twelve names.

Practical Examples You Can Use Right Now

Seeing the rules in action makes them easier to internalize. Here are clean, correct examples across the most common scenarios.

• APA in-text, three or more authors: (Thompson et al., 2019)

• APA narrative citation: Thompson et al. (2019) found that...

• MLA in-text, three or more authors: (Thompson et al. 34)

• MLA Works Cited entry start: Thompson, Aisha, et al. Title of Work...

• Chicago author-date, four or more authors: (Thompson et al. 2019)

• Two authors, any style: (Thompson and Okafor, 2019) -- never use et al. here

Print this list. Keep it next to your citation manager. The goal is not to memorize every rule cold but to know where to look and what to verify before you submit.

When Et Al. Appears in Sources You Are Reading

You will encounter et al. constantly as you read academic literature. When you see it, remember that the full author list exists in the reference section of that paper. If the authorship matters for your own citation purposes (for example, if you are citing a secondary source), locate the original reference and record all the author names properly. Do not simply copy a citation that uses et al. from another paper's reference list. The original source may have a different number of authors than you expect, and you need to apply your own style guide's rules from scratch.

This is especially relevant when you are conducting a literature review or a meta-analysis. If you want to understand the scope of that kind of research project, our guide on what a meta-analysis is for high school students walks through the process clearly. Accurate citation tracking across dozens of sources is part of what makes that kind of research credible.

Getting Your Citations Right Before Submission

Citation management tools like Zotero, Mendeley, and even Google Scholar's built-in export feature can generate citations automatically. Use them. But do not trust them blindly. Automated tools make errors, especially with non-standard sources, preprints, and works with large author lists. Always review every generated citation against your style guide before you submit. Et al. thresholds, period placement, and reference list formatting are exactly the kinds of details that automated tools sometimes get wrong.

If your paper gets accepted for publication, understanding how to represent that credential accurately matters too. Read our post on what accepted for publication means and when to claim it to handle that milestone correctly. And if you want to know what happens after your paper is live, our guide on what to do after your research paper gets published covers the next steps in detail.

Publication timing is another area where student researchers often have questions. Our post on what quarterly issue means for journal publication timing explains how journals schedule and release their issues, which affects when your work becomes publicly citable.

Conclusion: What Does Et Al. Mean and How to Use It

Understanding what et al. means and how to use it correctly is one of the clearest markers of citation competence. The abbreviation means "and others." It shortens multi-author citations in the body of your text. The rules for when to use it vary by citation style, but the underlying purpose is consistent: keep your writing readable while giving credit to everyone who contributed to the research you are citing.

Use et al. only for three or more authors (in most styles), always include the period after al., never use it in APA reference lists, and never apply it to two-author works. These are not arbitrary rules. They are the shared conventions that make academic communication precise and trustworthy across disciplines and institutions.

If you are a high school student preparing original research for submission to a peer-reviewed journal, getting these details right matters. At the Princeton Journal of Pre-Collegiate Research, we hold student work to the same rigorous standards as any serious academic publication (no shortcuts, no rubber stamps). Exceptional student research deserves an exceptional platform, and that starts with a manuscript that demonstrates command of the craft. Explore our research and publishing guides to build every dimension of that competence before you submit.