Apostrophes Used Incorrectly to Form Plurals

The exam tests this error constantly because it's an easy habit to fall into. A sign that reads 'fresh apple's daily' looks like it needs an apostrophe before the s, but ask what the apostrophe is doing. It's not showing that the apple owns anything, and no letters are missing. The writer just means more than one apple, and a plain plural needs nothing but s. The fix, apples, uses the s alone to do all the work.

An apostrophe has exactly two jobs: it marks possession (the apple's skin, meaning the skin belonging to the apple) or it marks a contraction, standing in for a dropped letter (it's for it is). A plural is neither of those things. It just counts more than one of something, so it gets s or es and nothing else. This rule holds even for numbers and names that look unusual in plural form: decades like the 1990s, abbreviations like CDs, and family surnames like the Harrises all take a bare plural ending, no apostrophe involved.

This sits next to apostrophes for possession and contraction because the three uses get tangled together on the page. Once a mark shows up between a word and its s, a reader has to ask which job it's doing: ownership, missing letters, or neither. If the answer is neither, the apostrophe has to go. Spotting a wrongly placed apostrophe is really the same skill as knowing where a correctly placed one belongs.