Common Errors in In-Text Citations (APA and MLA Fixes)

5 November 2026 · 6 min read

The most common errors in in-text citations are small formatting slips: a missing page number for a quote, the wrong use of "et al.," an ampersand where "and" belongs, a comma in the wrong place, or a citation that doesn't match any entry in the reference list. Each one is easy to fix once you know the rule. This guide covers the mistakes that come up most often in APA 7th edition and MLA 9th edition, with wrong and corrected versions side by side.

Why in-text citations matter

An in-text citation is a pointer. It tells the reader which entry in your reference list or works cited page supports a specific sentence. If the pointer is broken, by naming a different author, giving a different year or leaving out a page, the reader can't check your evidence. Instructors also read citation errors as a sign of careless source handling, which can cost marks even when the research itself is solid.

The quick reference

Keep this table nearby and you'll catch most problems on a read-through.

Error 1: Leaving out the page number for a direct quote

APA, wrong: "Sleep loss shapes mood more than diet does" (Patel, 2020). APA, correct: "Sleep loss shapes mood more than diet does" (Patel, 2020, p. 112).

APA requires a page number (or another locator, such as a paragraph number for unpaginated web pages) whenever you quote directly. For paraphrases it is encouraged but not required.

In MLA, the page number is the core of the citation. If the source has page numbers, include them for both quotes and paraphrases where you can point to a specific passage.

Error 2: Adding a comma or "p." in MLA

MLA, wrong: (Patel, p. 112) MLA, correct: (Patel 112)

MLA uses no comma between author and page, and no "p." or "pg." This is the single most common slip for students who switch between APA and MLA.

Error 3: Using "&" and "and" in the wrong places

APA uses an ampersand inside parentheses and the word "and" in running text.

APA, wrong: (Garcia and Holm, 2019) ... Garcia & Holm (2019) found... APA, correct: (Garcia & Holm, 2019) ... Garcia and Holm (2019) found...

MLA always uses "and," never an ampersand.

Error 4: Getting "et al." wrong

Both APA 7 and MLA 9 use "et al." from the first citation when a source has three or more authors. Older editions had different rules (APA 6 listed up to five authors on first mention), which is why outdated guides cause confusion.

Wrong: (Kim, Osei, & Park, 2022) on first mention in APA 7 Correct: (Kim et al., 2022)

Also watch the punctuation. "Et" is a full word, so it has no period. "Al." is an abbreviation, so it does.

Wrong: et. al., et al, etal. Correct: et al.

Error 5: Including first names or initials

Wrong: (Maria Lopez, 2018) or (M. Lopez 33) Correct: (Lopez, 2018) or (Lopez 33)

Use surnames only. The exception: in APA, if two different first authors share a surname in your reference list, add initials to tell them apart: (J. Lopez, 2018; M. Lopez, 2021).

Error 6: Citations that don't match the reference list

This is the error that hurts most, because it suggests you didn't check your sources. Common versions:

• The in-text year is 2019 but the reference says 2020.
• The in-text author is spelled differently from the reference.
• A source is cited in the text but missing from the list, or listed but never cited (APA expects every reference to be cited and vice versa; MLA's works cited also lists only what you cite).

Fix it by doing one final pass where you check every in-text citation against the list, one by one.

Error 7: Citing the wrong author for a quoted source

If you read a quote from Smith inside a book by Jones, and you never saw Smith's original, you need a secondary citation.

APA: Smith (as cited in Jones, 2017, p. 54) claimed... Only Jones goes in the reference list.

MLA: Smith claimed that... (qtd. in Jones 54) Only Jones goes in the works cited.

Citing Smith directly implies you read Smith, which you didn't. Where possible, find and read the original.

Error 8: Mishandling sources without an author

When there is no individual author, use the organisation as author if there is one. If there truly isn't one, use the title.

APA: (World Health Organization, 2023) or ("Coastal Erosion Explained," 2022) MLA: (World Health Organization 14) or ("Coastal Erosion Explained")

Don't write "Anonymous" unless the work is actually signed that way. Shorten long titles in the citation to the first few words, and format them as they appear in the list: italics for standalone works, quotation marks for parts of larger works.

Error 9: Missing or wrong dates in APA

• Use "n.d." when there is no date: (Harris, n.d.).
• Use only the year in the in-text citation, even if the reference includes a month and day.
• For multiple works by the same author in the same year, add letters: (Chen, 2020a, 2020b), and match those letters in the reference list.

Error 10: Over-citing and under-citing

Over-citing means repeating the same parenthetical after every sentence in a paragraph drawn from one source. In APA, once you've cited a source in a paragraph with a narrative citation, you can generally omit the year in later narrative mentions within that same paragraph. In both styles, write so it's clear you're still discussing the same source, then cite again when the source changes or ambiguity creeps in.

Under-citing is more dangerous. If a paragraph uses ideas from a source, cite it, even when you haven't quoted. Missing citations for paraphrased material is one of the most common routes into accidental plagiarism.

Error 11: Punctuation around the citation

The citation sits before the sentence's final punctuation in most cases.

Wrong: Rates fell sharply. (Ibrahim, 2021) Correct: Rates fell sharply (Ibrahim, 2021).

For block quotations (40+ words in APA, more than four lines of prose in MLA), the citation goes after the final punctuation of the block.

A final-check routine

1. Search your document for every opening parenthesis and check each citation format.
2. Search for "et al" and confirm the period placement.
3. Search for "&" and confirm each is inside parentheses (APA) or remove it (MLA).
4. Check every quote has a page or locator.
5. Tick off each reference list entry as you find its matching in-text citation.

Generating reference entries with a tool like Inkwell's APA citation generator or MLA citation generator reduces formatting slips, but always compare the output with your source and with the in-text citation you wrote. A bibliography generator can help keep the full list consistent.

FAQ

Do I need a page number for paraphrases?

In APA 7 it is recommended but not required, especially when it would help a reader find the passage. In MLA 9, include the page number whenever the paraphrase comes from a specific part of a paginated source.

When do I use "et al." in APA 7?

From the very first citation for any source with three or more authors. In the reference list itself, you list up to 20 authors.

What if a website has no page numbers?

Omit the page number. In APA you can add a paragraph number or section heading for a direct quote, such as (Lee, 2022, para. 4). In MLA you can use a paragraph or section number if the source numbers them; otherwise give the author alone.

Is a citation error the same as plagiarism?

Not usually. A formatting mistake on a properly credited source is a citation error. Plagiarism means failing to credit the source at all, or presenting it as your own. However, repeated or serious citation failures can be treated as plagiarism under some policies.