What Does Et Al Mean? How to Use Et Al in Academic Referencing

What does et al mean?

Et al is a Latin abbreviation meaning "and others." It is derived from the Latin phrase et alii (masculine), et aliae (feminine), or et alia (neuter), all of which translate as "and others." In academic writing, et al is used in place of a full list of authors when a source has multiple contributors, allowing citations to remain concise without omitting the required attribution.

The abbreviation is used across all major citation styles, including Harvard, APA, MLA, Chicago, and Vancouver, though the precise rules governing when et al should be used differ between styles. Understanding these differences is important for students working across disciplines, as applying the wrong convention for the relevant style is one of the most frequently penalised referencing errors in UK university assignments.

How to write et al correctly

Et al should always be written with a full stop after "al" because "al" is an abbreviation of "alii" or its variants. The correct form is therefore et al. with a period. Writing "et al" without the full stop is technically incorrect, though some institutions and journals accept it. The word "et" is a complete Latin word meaning "and" and does not require a full stop after it.

In most citation styles, et al is not italicised in the body of the text. APA 7th edition, for instance, does not italicise et al in in-text citations. Some older style guides italicised Latin abbreviations as a matter of convention, but this practice is no longer standard in most current editions of major referencing guides.

Et al in Harvard referencing

In Harvard referencing, et al is used when a source has three or more authors. For works with two authors, both surnames are given in the in-text citation, joined by "and." For works with three or more authors, only the first author's surname is given, followed by et al. and the year of publication.

For example, a work by Smith, Jones, and Brown published in 2022 would be cited as: (Smith et al., 2022). In the reference list, all authors are always listed in full, regardless of how many there are. The use of et al is confined to in-text citations in Harvard referencing.

Et al in APA 7th edition

APA 7th edition uses et al for works with three or more authors, which represents a change from APA 6th edition, where et al was only used from the first citation for works with six or more authors. Under APA 7th edition, a work with three or more authors is cited with only the first author's surname followed by et al. from the very first citation.

For a work by Smith, Jones, Brown, and Williams published in 2021, the APA 7th in-text citation would be: (Smith et al., 2021). For works with two authors, both surnames are given in every citation, joined by an ampersand: (Smith and Jones, 2021) in the narrative form, or (Smith and Jones, 2021) in the parenthetical form.

Et al in MLA 9th edition

MLA 9th edition uses et al for works with three or more authors. For a work by Marshall McLuhan, Robert Logan, and James Carey, the MLA in-text citation would be: (McLuhan et al. 45), where 45 is the page number. Note that MLA in-text citations give the author's surname and the page number, with no comma between them.

In the Works Cited list, MLA uses "et al." after the first author's name when a source has three or more authors: McLuhan, Marshall, et al. This is one of the key differences between MLA and other styles, which typically list all authors in full in the reference list.

Et al in Chicago 17th edition

Chicago 17th edition (Notes-Bibliography system) uses et al for works with four or more authors in footnotes and shortened notes, and for works with ten or more authors in the bibliography. For a work with up to three authors, all names are listed. For a work with four to ten authors, et al is used in notes but all authors are listed in the bibliography up to ten.

In the author-date system (Chicago's alternative to Notes-Bibliography, used in social sciences), et al is used for works with three or more authors, similar to APA. The in-text citation would appear as: (Smith et al. 2022).

Et al in Vancouver referencing

Vancouver referencing, used in medicine and the life sciences, uses et al for works with more than six authors. If a source has six or fewer authors, all are listed in the reference. If there are seven or more, the first six are listed followed by et al. This convention follows the guidelines of the International Committee of Medical Journal Editors (ICMJE).

Vancouver references are numbered rather than author-date, so et al appears in the reference list rather than in in-text citations. An in-text Vancouver citation is simply a number in square brackets: [1].

Common mistakes with et al

The most common error is using et al for two-author sources. In all major citation styles, both authors must be named when a source has only two contributors. Et al is reserved for sources with three or more authors in Harvard, APA, and MLA, and for sources with four or more in Chicago Notes-Bibliography.

A second frequent error is omitting the full stop after "al." Since "al" is an abbreviation, it requires a period. Writing "et al" without the period is incorrect in formal academic writing, regardless of the citation style being used.

A third error is using the plural "et als." or treating et al as if it needs to be followed by additional information. Et al already means "and others" and is complete as written. Adding further names after et al defeats the purpose of the abbreviation. If in doubt about how to cite a source correctly, GradeQuill's Academic Referencing Generator formats et al automatically for all five major citation styles.