APA Punctuation Rules: Colons, Apostrophes, and Quotation Marks Done Right

Punctuation errors in APA writing are easy to overlook because most of them look correct. A straight apostrophe instead of a curly one, a colon after an incomplete sentence, quotation marks placed outside a period instead of inside. None of these leap off the page the way a missing citation does. But they show up consistently in dissertation feedback, and they matter.

Colons

A colon in APA writing must follow a complete sentence. "The study identified three themes:" is incorrect because what comes before the colon is not a complete sentence. "The study identified three themes, which included the following:" is correct. This rule applies to colons that introduce lists, quotations, and explanations. Read the text before every colon in your document and verify that it could stand alone as a complete sentence.

Apostrophes and Quotation Marks

APA requires smart (curly) apostrophes and quotation marks, not straight ones. Straight marks look like this: ' and "". Smart marks curve toward the text they are attached to. This distinction matters because straight marks are common in text copied from websites, Google Docs, or other online sources, and they carry over into Word documents without any visible warning.

To fix this, use Find and Replace in Word to search for straight apostrophes and replace them with smart ones. Then do the same for straight quotation marks. Word's autocorrect typically converts these automatically as you type, but copied text bypasses that feature entirely.

Quotation Mark Placement

In APA style, periods and commas go inside quotation marks, not outside. "The results were significant," is correct. "The results were significant", is not. This differs from British English conventions, which is why it catches international students off guard. End quotation marks go after commas and periods in every case.

Ellipses

When you omit text within a quotation, use three spaced dots with a space before and after each one. When the omission falls between two sentences, add a period before the ellipsis. The format is: period, space, three dots each separated by spaces, space (". . . ."). When copying quotations from sources, check every ellipsis to make sure it follows this format rather than using a single ellipsis character.

Pseudonyms and Quotation Marks

When you introduce a pseudonym for a research participant, you use quotation marks around the name the first time it appears to signal that it is a pseudonym. After that first introduction, drop the quotation marks. Using quotation marks around the pseudonym every time it appears is a common error that makes the writing feel inconsistent.