How and when to use et al.
“Et al.” is short for the Latin term “et alia,” meaning “and others.” It is used in academic citations when referring to a source with multiple authors:
Different citation styles have different rules for when to use “et al.” Below, we explain the rules for APA, MLA, and Chicago.
Common mistakes
There are a couple of common mistakes to watch out for when using “et al.”
Punctuation
The “al” in “et al.” is always followed by a period. This is because the term is an abbreviation of the Latin phrase “et alia”—the period indicates that it is an abbreviation:
- et al
- et. al
- et. al.
- et al.
“Et al.” may be directly followed by other punctuation where necessary, but the period always comes first:
When “et al.” comes right at the end of a sentence, only one period is used:
Et al. vs. etc.
“Et al.” should not be confused with “etc.”; it is used for lists of people, whereas “etc.” is used for lists of things and concepts:
Using et al. in APA Style
In APA Style in-text citations, when a source has two authors, list both. When there are three or more authors, cite the first author followed by “et al.”
| Number of authors | In-text citation |
|---|---|
| 1–2 authors | (Anderson & Singh, 2018) |
| 3+ authors | (McDonnell et al., 2019) |
APA does not recommend using “et al.” in the reference list. Instead, list up to 20 authors in full. When a source has more than 20 authors, list the first 19, then an ellipsis (…), then the final name:
6th edition rules
The rules above apply to the 7th edition of the APA manual. If you’re instructed to follow the 6th edition, the use of “et al.” is slightly different.
For sources with three to five authors, list all the authors the first time, and use “et al.” only in subsequent citations. For sources with six or more authors, use “et al.” from the first citation.
| Number of authors | First citation | Subsequent citations |
|---|---|---|
| 3–5 authors | (Smith, Sanchez, Davies, Baldwin, & Caulfield, 2016) | (Smith et al., 2016) |
| 6+ authors | (McDonnell et al., 2016) | (McDonnell et al., 2016) |
Using et al. in MLA style
In MLA style, always use “et al.” for sources with three or more authors. This applies both to in-text citations and in the Works Cited list.
| Number of authors | In-text citation example | Works cited example |
|---|---|---|
| 1–2 authors | (Smith and Davies) | Smith, Joshua, and Robert Davies. … |
| 3+ authors | (McDonnell et al.) | McDonnell, Frederick, et al. … |
Using et al. in Chicago style
Chicago style has two systems of citation: notes and bibliography, and author-date style. The use of “et al.” is the same in both styles.
For sources with one, two, or three authors, list all author names in your in-text citations (whether footnotes or author-date). For sources with four or more authors, use the first name followed by “et al.”
| Number of authors | Footnote example | Author-date example |
|---|---|---|
| 1–3 authors | 1. Joshua Smith and Robert Davies,… | (Smith and Davies 2019) |
| 4+ authors | 2. James Simpson et al., … | Simpson et al., … |
In your Chicago style reference list or bibliography, list up to 10 authors. If a source has more than 10 authors, list the first seven followed by “et al.”:
12 comments
Baris
September 17, 2021 at 11:55 AMHi Jack,
What about in the case of co-authorship? I'm not sure about other disciplines but in biological science journals, an asterisk is used to indicate co-authorship. And we see in the footnote the following statement: *These authors contributed equally to this work. Is the sole purpose of et al. citations simplicity or giving credit fairly? In relation to this, what would be the citation for an article that has been written by two co-authors who have contributed equally?
Thanks in advance!
Jack Caulfield (Scribbr Team)
September 21, 2021 at 1:42 PMHi Baris,
This is a tricky issue that style guides don't tend to get into. The purpose of using "et al." is not to highlight anyone's contribution as more important than that of the other authors, but simply to save space in your citations. The name of the first author listed is used just for the sake of convenience, and it's down to the publisher and authors, not the person citing the source, to determine the order in which authors are listed. But of course, it's not unreasonable to think the author who is directly named is receiving more direct credit for their work than those who are not named.
Nevertheless, there's no coverage of exceptions to the rule of using "et al." in APA, MLA, or Chicago, so it's reasonable to assume they would advise just using "et al." even in a case like the one you describe.
Mehdi
May 28, 2021 at 9:49 AMHi,
Which one is correct ?
In Smith et al.'s study.
In Smith et al.s' study.
Jack Caulfield (Scribbr Team)
May 31, 2021 at 3:30 PMHi Mehdi,
Usually it's best to avoid this kind of phrasing, e.g. by changing it to "In a study by Smith et al." or "Smith et al. (2015) found that . . .". However, where this is not possible, the correct option is "Smith et al.'s study."
Dawn Gordon
May 27, 2021 at 1:24 AMI wanted to find out if Et al. can be used in addressing persons when sending an email, instead of referencing all names in salutation.
Jack Caulfield (Scribbr Team)
May 31, 2021 at 3:39 PMHi Dawn,
It's usually best to avoid this usage of et al., as it may be considered rude (especially as it involves naming one of your addressees but not others). If it's too unwieldy to list all names, an appropriate general term should be used, e.g. "Dear colleagues" or similar.
John
September 15, 2021 at 1:28 AMJack,
My question is similar, yet different, from Dawn's, so I thought I'd tag along on this string:
Is it inappropriate, offensive, etc. greet email recipients with "Ladies, Gentlemen, Et al., ..."?
I understand & agree that naming some and not others is offensive.
However, I lead a staff of professionals with a sprinkling of diversity, and would like to counter the minority that are not so accepting. So, I would like to promote an inclusive environment in little ways.
Jack Caulfield (Scribbr Team)
September 21, 2021 at 1:31 PMHi John,
I don't personally see anything offensive about that phrasing (though of course I can't account for how others would react to it!). I wouldn't capitalize "et al." though; it's a phrase rather than a name.
Carlos D. Martinez Sanchez
May 1, 2021 at 9:31 AMHello Jack,
I've got a question regarding whether or not this applies to translators as well. Take this for example, I want to cite "Mexican Masks" by Octavio Paz. He, alone, is the author for this essay. However, I read the translated version by Lysander Kemp, Yara Milos, and Rachel Phillips. I was wondering if I could list Lysander Kemp as a translator and then add "et al." as follows: Paz, Octavio. "Mexican Masks." The Labyrinth of Solitude. Translated by Lysander Kemp et al. Grove Press Inc, 1985.
Jack Caulfield (Scribbr Team)
May 3, 2021 at 4:59 PMHi Carlos,
Yep, indeed you can use et al. for multiple translators just as you would for multiple authors. Note that you'd need a comma after "et al." though, as there would usually be a comma there for this format: Lysander Kemp et al., Grove …
Bonginkosi
April 9, 2021 at 5:01 PMQuestion
When my sources have different publication dates. Which date do I use with et al.?
Jack Caulfield (Scribbr Team)
April 16, 2021 at 3:13 PMHi Bonginkosi,
I'm not sure I understand your question. You should cite each source separately, not combine different sources into one citation. You use et al. when a single source has multiple authors, not to combine the authors of different sources. So this issue shouldn't come up.
Hope that helps; let me know if I've misunderstood what you were asking!