Grammar Rules: Irregular Plurals and Double Possessives

Grammar Rules: Irregular Plurals and Double Possessives

Experts and style guides have argued over how to make do and don’t plural for decades. And don’t get me started on double possessives. These are two very difficult concepts to grasp a hold of in the English language. However, I am going to give you which rules are most widely accepted. Come take a look. 

1. Adding An Apostrophe For Plural Forms

Apostrophes show possession or indicate a contraction. But in this case, I will throw that rule out the window. Now, it works well for do, but it gets a tad bit confusing once you apply the same concept to don’t. Let me show you what I mean. 

  • I created a list of do’s and don’t’s. 

I hate the way that look looks. Don’t you??? Here are some other ways that you can accomplish the same goal without it appearing to be grammatically incorrect. 

  • I created a list of dos and don’ts. (Chicago Manual) 
  • I created a list of do’s and don’ts. (Associated Press, and my personal favorite, lol) 

Long story short, things can definitely start to get complicated when using apostrophes for plurals as opposed to possession. 

2. Making Do A Noun

Most often the do is tied to another word, making it a noun. For example: 

  • I am getting a new hairdo for my birthday. 
  • She places her to-do list inside of her agenda. 

Now, if you want to make these nouns plural, you can choose to write them with or without the apostrophe. 

  • My beautician has to do four hairdos before the end of the day. 
  • I hope I will have a short list of to-do’s tomorrow. 

With the sentences above, I would prefer to use the apostrophe. However, either way is acceptable. 

3. Making Acronyms, Abbreviations, And Decades Plural

Many style guides will instruct you to refrain from using apostrophes to make acronyms and abbreviations plural in formal writing. Though it is generally accepted with informal writing, you can avoid this rule altogether by simply using a lowercase s and discarding the apostrophe.

  • My cousin finally have away all of her CD’s (or CDs).
  • My father was born in the 1960’s (or 1960s). 

In formal writing, you should type out the acronyms in full words utilizing lowercase letters. It is a straightforward approach that eliminates confusion.

  • My cousin finally gave away all of her compact discs. 
  • My father was born in the nineteen-sixties. 

4. Writing Double Possessives Correctly 

Have you ever wondered how you should make a noun plural that already shows possession? I have! But I always try to rewrite the sentence to avoid this situation. Otherwise, you may give yourself a grammatical headache. 

  • McDonald’s has the best hamburgers. 
  • Wendy’s has the best fries. 

Now, what if I want to make these nouns possessive?

  • McDonald’s’s hamburgers are the best! 
  • Wendy’s’s fries are the best! 

Some may say that because the noun ends in an s, all that needs to be added is an apostrophe so that it looks like this: 

  • McDonald’s’ hamburgers are the best! 
  • Wendy’s’ fries are the best! 

Either way is hard on the eyes. I would opt to use the first set of sentences to avoid this issue. 

Every once in a while, you come across difficult concepts like the ones I’ve mentioned in this article today. I suggest choosing a style that works well for you and staying consistent. Once you get into the habit of following the rule set you’ve chosen, you’ll find that it’s a lot easier to maneuver through these sorts of challenges. If you need further assistance, you can contact I A.M. Editing, Ink at with all of your questions. 

Adrienne Michelle Horn is the owner of I A.M. Editing, Ink. Although she has a full-time professional career in the healthcare field, she is also a South Florida-based editor, poet, author, entrepreneur, and mother of her beautiful daughter, Paris.

For more information about Adrienne and her company, follow I A.M. Editing, Ink on social media or visit