APA 7 vs MLA 9: which one your class probably wants

APA and MLA solve the same problem in different ways. Both tell a reader where your information came from, and both do it in two places: a short note in the text and a full entry in a list at the end. They differ in what the note says, what the entry contains, and how titles and names are written.

Your instructor decides which one you use. This post shows the differences on one real article, explains how to find out which style your course wants, and lists the mistakes people make when they switch from one to the other.

Start with the assignment, not the subject

Check these in order:

1. The assignment sheet. It often names the style and the edition.
2. The syllabus or course site. Many courses state a style once, for every paper.
3. Your instructor. If neither says, ask. “APA 7 or MLA 9?” is a one-line email.

If an instructor says any style is fine, pick one and use it throughout. Mixing the two in one paper is the one thing to avoid.

Which subjects use which

APA describes its style as a set of guidelines used by millions of people in psychology, the social sciences and many other disciplines. It also names nursing, education, business, communications and engineering among the fields that use it. The first version dates from 1929, and the current manual is the seventh edition.

MLA style comes from the Modern Language Association, founded in 1883, whose members study and teach language and literature. It is common in literature, language and other humanities courses. The current handbook is the ninth edition, published in 2021.

These are habits, not rules. A department can choose either one, and a few use neither: Chicago, Harvard and IEEE are the others students meet most often. The assignment decides.

One article, both styles

The example is a real journal article: Knill and Pouget’s 2004 paper in Trends in Neurosciences, with DOI 10.1016/j.tins.2004.10.007. The two entries below come from PaperCitation’s formatter, using the article’s published record.

APA 7, in the reference list:

Knill, D. C., & Pouget, A. (2004). The Bayesian brain: the role of uncertainty in neural coding and computation. Trends in Neurosciences, 27(12), 712–719. https://doi.org/10.1016/j.tins.2004.10.007

MLA 9, in the Works Cited list:

Knill, David C., and Alexandre Pouget. “The Bayesian Brain: The Role of Uncertainty in Neural Coding and Computation.” Trends in Neurosciences, vol. 27, no. 12, 2004, pp. 712–19, https://doi.org/10.1016/j.tins.2004.10.007.

In the text: APA gives (Knill & Pouget, 2004). MLA gives (Knill and Pouget), with a page number added when you point to a specific part of the article.

The differences you can see in that example

• Author names. APA gives the surname and initials: Knill, D. C. MLA gives the full name as the source prints it: Knill, David C. With two authors, APA puts an ampersand before the last name, and MLA writes “and.”
• Where the date goes. In APA the year sits in parentheses right after the authors. In MLA it comes later in the entry, after the volume and issue.
• Title capitalization. APA writes article titles in sentence case: only the first word, the first word after a colon and proper nouns are capitalized. MLA uses title case. Neither style italicizes an article title, but MLA puts it in quotation marks and APA does not. The journal name is italic in both.
• Volume and issue. APA writes 27(12), with the volume in italics and the issue in parentheses. MLA spells out the labels: vol. 27, no. 12.
• The DOI and the end of the entry. Both styles write the DOI as a full link beginning with https://doi.org/. An MLA entry ends with a period after the link. APA says not to put a period after a DOI, because it can interfere with the link.
• Three or more authors. APA lists the authors in the reference list, up to 20. MLA gives the first author followed by “et al.” In the text, both styles use the first author plus “et al.” for three or more authors, and APA does so from the very first citation.
• The name of the list. APA calls it References. MLA calls it Works Cited.

In-text citations

This is the difference readers notice first.

APA uses author and year. A parenthetical citation puts an ampersand between two names: (Salas & D’Agostino, 2020). A narrative citation, where the names are part of your sentence, spells out “and”: Salas and D’Agostino (2020). For a direct quotation, APA also requires a page number or other location, as in the APA page’s own example, (Ervin et al., 2018, p. 470). APA does not use “ibid.” When you cite the same source again in a parenthetical citation, you give the author and year again.

MLA uses author and page. There is no year and no comma. MLA’s own example is (Baron 194). The page number appears when you quote or paraphrase a specific part of a source that has pages. If you name the author in your sentence, only the page goes in the parentheses, and you do not repeat the name in both places.

A source with no page numbers is the same problem in both styles. APA allows another location, such as a paragraph number, for a quotation. In MLA you leave the page number out.

What the two have in common

• Every in-text citation points to one entry in the list. A source that appears in the list but is never cited in the text, or the reverse, is a mistake in both styles.
• DOIs are written as https://doi.org/ links. If the work has a DOI, both styles want it.
• Entries are alphabetical by author. Both lists are alphabetical, and both ask for a half-inch hanging indent on every entry.

Mistakes when you switch

Students who know one style tend to carry its habits into the other:

• A year in an MLA in-text citation. MLA gives the author and the page.
• An ampersand in an MLA entry. MLA writes “and.”
• Title case in an APA reference. APA wants sentence case. Databases often store titles in title case, so convert them. Check proper nouns afterward, because a program cannot always tell a name from an ordinary word.
• A missing issue number in an APA reference. APA asks for the issue number of a journal article.
• “Retrieved from” before a DOI. APA does not use it.
• A period after an APA DOI. An MLA entry ends with one, and an APA entry does not.

Editions

The rules above are for APA’s seventh edition and MLA’s ninth. Older handbooks differ in places, and some instructors still hand out older guides. If your instructor’s examples do not match what you see here, ask which edition the course uses.

Letting a tool do the formatting

Formatting by hand is slow and the errors are easy to miss. PaperCitation’s APA and MLA generators build an entry from a DOI, an ISBN or a web address, and the same record can be formatted in either style. For one DOI, DOI to citation does it directly. The how-to guides for a journal article in APA and in MLA go through each part of the entry.

A generator can still get a detail wrong, especially with unusual titles, names and sources. Compare its output with your instructor’s examples before you paste it into your paper. To check that the references in a finished list exist and match their published records, run the list through the reference checker.