Today’s grammar tip: Apostrophes and plurals.

In most cases, plurals should not be formed using an apostrophe. Nowadays this typo is particularly tricky to rein in because autocorrect seems to think we all want “taco’s” on “Tuesday’s” with our “mom’s.” But don’t let your phone bully you into bad grammar! You actually want tacos on Tuesdays. Everyone does. Even moms.

You might also see this typo on invitations, holiday cards, or mailboxes in an effort to make a last name plural. For most family names, just add an s. But if your last name ends with j, s, x, z, ch, or sh, you’ll want to add es. These rules are important to remember for when you invite the Murphys, Caputos, Lopezes, and Rajes to your weekly taco night. And it’ll certainly help you keep up with the Joneses.

So when should you use an apostrophe to form a plural? When your audience might misread it. For example, “there are four is in ‘Mississippi’” looks pretty confusing. But “there are four i’s in ‘Mississippi’” is much clearer. Similarly, Crowley Webb’s preferred style is to use the phrase “do’s and don’ts” even though it should technically be “dos and don’ts” according to our preferred style guide (Chicago Manual of Style) and our preferred dictionary (Merriam-Webster). The alternative spelling we use is accepted by some styles and dictionaries, and our goal in employing the added apostrophe is to provide clarity for the sake of the reader.

For more on unique and interesting plurals, check out Grammar Girl’s posts on making family names plural and on the phrase “dos and don’ts.”