How to use et al for different referencing and citation styles.
It’s a good idea to know how to properly cite your sources before you start writing. With this in mind, you should understand how to write et al in a citation before you start pulling everything together.
Below, we explore how to use et al for different referencing types, so you’re covered whatever system your school or organisation uses.
How to write et al in Harvard referencing.
How you use et al in Harvard referencing is simple – you need to use ‘et al’ in your in-text citation if there are more than three authors, but list all of the authors in your reference list. However, there are some slight differences depending on the type of source you’re using.
For example:
Books and eBooks.
In-text citation:
‘According to Simpson et al. (2022), the reason for the issue was…’
Reference list:
Simpson, N., Jones, L.H., Davidson, M. and Scott, P. (2022) The Changing of the Seasons. 2nd edn. Cambridge: Cambridge University Press.
Articles.
In-text citation:
‘The mitochondria is often described as the engine room of the cell (Johnson et al., 1998, p.56).’
Reference list:
Johnson, P., Hutchinson, P., Abercrombie, H.M., Lewisham, D. (1998) ‘Why Mitochondria Are So Great’ Journal of Science Things, 13(10), pp.56-59.
How to write et al in APA referencing.
How you write et al in APA referencing depends on the edition you’re using – e.g. 6th or 7th. You should check with your school or organisation what edition you need to follow before getting started.
6th edition et al rules.
For sources with 3-5 authors, list the surnames of all the authors in the first citation, then use et al for all subsequent citations.
Examples:
- First citation: ‘The reason for the issue was because summer is the hottest season of the year (Simpson, Jones, Davidson & Scott, 2022)…’
- Further citations: ‘The reason for the issue was because summer is the hottest season of the year (Simpson et al., 2022)…’
For sources with 6 or more authors, always use et al in your in-text citations.
Example:
- ‘The reason for the issue was because summer is the hottest season of the year (Simpson et al., 2022)…’
7th edition et al rules.
For sources with 1-2 authors, you should list both.
Example:
- ‘The mitochondria is often described as the engine room of the cell (Johnson & Hutchinson, 1998).
For sources with 3 or more authors, use et al.
Example:
- ‘The mitochondria is often described as the engine room of the cell (Johnson et al., 1998).’
How to write et al in MLA referencing.
For MLA referencing, you should use ‘et al’ to cite sources with 3 or more authors. This stands for both in-text citations and your list of Works Cited (the reference list/bibliography).
- Sources with 1-2 authors – ‘The reason for the issue was because summer is the hottest season of the year (Simpson and Jones)…’
- Sources with 3 or more authors – ‘The reason for the issue was because summer is the hottest season of the year (Simpson et al., 2022)…’
Importantly, if you’re referencing a source within the context of a sentence, you should not use ‘et al’, rather ‘and colleagues’. For example:
‘According to Simpson and colleagues (45), the reason for the issue was…’
How to write et al in Chicago referencing.
Chicago-style referencing uses the same et al rule for citations, whether it’s for the notes and bibliography or author-date style system. Notably, Chicago referencing doesn’t use in-text citations, but rather footnotes.
For sources with 1-3 authors, you’ll need to list all the names in full in the footnotes. For sources with 4 or more authors, list the first name in full, followed by ‘et al.’
- Sources with 1-3 authors – Paula Johnson, Peter Hutchinson and Harold Abercrombie, Why Mitochondria Are So Great (Journal of Science Things, 1998), 56-9.
- Sources with 4 or more authors – Paula Johnson et al., Why Mitochondria Are So Great (Journal of Science Things, 1998), 56-9.
Common mistakes to avoid when writing et al.
As with any referencing, it can be easy to make small mistakes. Here are some of the most common things to watch out for:
- Plural vs. singular verbs. ‘Et al’ refers to multiple people, so you need to use plural verbs. For example, ‘Simpson et al. state that…’
- ‘Et al’ and ‘etc’. These two do not mean the same thing, so they shouldn’t be used interchangeably. ‘Et al’ is used for lists of people, while ‘etc’ is used for lists of nouns and concepts.
- Known when to use punctuation and italics. ‘Et al.’ should only be written in italics with a full-stop at the end for Harvard referencing.
- In-text citations vs. bibliographies. ‘Et al’ should only be used in in-text citations – in most cases. Some referencing styles (like MLA) also ask for it in the Works Cited list.