The Only Time to Use Apostrophes for Plurals

Khan Academy

This concise grammar tutorial clarifies the single, specific instance where it is grammatically correct to use an apostrophe to make a word plural. The narrators, Paige and David, explain that while apostrophes are generally reserved for possession or contractions, there is one rare exception: pluralizing lowercase letters to prevent confusion with other words. Using the example of "dotting your i's," they demonstrate how omitting the apostrophe would create the word "is," causing readability issues. The video contrasts this rule with uppercase letters and acronyms (like "CDs" or "MP3s"), reinforcing that these do not require apostrophes because they are unlikely to be confused for other words. Through clear visual examples on a blackboard style interface, the video debunks the common error of using apostrophes for all plurals, famously known as the "grocer's apostrophe." This resource is highly valuable for English Language Arts classrooms as it addresses a specific nuisance in punctuation rules that often confuses students. It provides a logical framework—clarity—for understanding punctuation exceptions rather than just memorizing arbitrary rules. Teachers can use this to correct common writing errors and help students understand the functional purpose of punctuation marks in conveying clear meaning.