When to Use an Apostrophe in Your Writing

Apostrophes are just one of the punctuation marks we use on a regular basis. However, are you sure that you’re using it correctly? Many people make the mistake of underusing or overusing apostrophes in their writing. To ensure that you’re not one of them, here are some things you should know about when to use an apostrophe.

When to Use an Apostrophe: Possession – Singular

When showing that something belongs to someone or something, you use an apostrophe. To do this, you’ll typically add an apostrophe and then the letter -s. For example, to answer the question “Is this your cup?” you could say, “No. It’s Marlin’s cup.” Since the cup belongs to Marlin, you need to add the apostrophe and -s after his name. Other examples of possession with singular subjects include:

  • Shari’s coat
  • today’s weather
  • the turtle’s shell
  • my son’s socks

But what happens if the word doing the possessing already ends with the letter s? Plan on adding the apostrophe at the end of the word, and, if it sounds okay, add an additional -s after it. However, this is a stylistic choice, and in most cases you can just drop the additional s at the end of the word. So, you could refer to Charles’s book or Charles’ book.

When to Use an Apostrophe: Possession – Plural

For plural subjects, add an -s and then an apostrophe. Back to the example above, maybe you have more than one son and you’re referring to the socks that belong to all of them. Then, you would add -s to “son” and say “my sons’ socks.” Other examples include:

  • the girls’ clothes
  • the workers’ time
  • the students’ work
  • the trees’ leaves

If you have an irregular plural noun, you should treat it like a singular possessive noun. Some of the irregular plural nouns you may come across are:

  • the women’s ideas
  • the children’s toys
  • the mice’s food
  • the men’s shoes
  • the people’s leader

When to Use an Apostrophe: Possession – Multiple Subjects

People often wonder how to use an apostrophe when writing about multiple subjects. For example, if you’re discussing the babies of Mike and Mollie, should both subjects have an apostrophe? In this example, the babies belong to both Mike and Mollie. Therefore, you only need to use one apostrophe—Mike and Mollie’s babies. If, however, Mike and Mollie each have a baby that doesn’t belong to the other person, you should say Mike’s and Mollie’s babies.

A great example to help you remember is found in the ice cream aisle of your grocery store. You don’t buy Ben’s and Jerry’s ice cream; you buy Ben and Jerry’s ice cream, because the company belongs to both Ben and Jerry.

When to Use an Apostrophe: Contractions

When forming contractions, you meld two words together and replace the missing letter(s) with an apostrophe. Some of the ones you might see are:

  • can not → can’t
  • will not → won’t
  • I am → I’m
  • he is → he’s
  • would not → wouldn’t
  • we have → we’ve
  • it is → it’s
  • you are → you’re
  • we are → we’re
  • they are → they’re
  • is not → isn’t
  • are not → aren’t
  • do not → don’t
  • who is → who’s

Contractions are typically used in less formal writing to make your writing sound more conversational.

When to Use an Apostrophe: Years

Similar to making contractions, an apostrophe should be used with years when omitting numbers. If you’re talking about the 1950s, you could drop the first two numbers and leave it as the ‘50s. Check out these sentences:

    The phrase “Far out!” originated in the ‘70s. People used it when talking about something that they thought was cool.
    During the ‘90s, we enjoyed trading pogs with friends at school.

If you choose to write out the entire year, just remember that you shouldn’t add an apostrophe between the year and the letter s. This isn’t grammatically correct, unless the year is possessing something.

    Incorrect: 1960’s
    Correct: 1960s

When to Use an Apostrophe: Letters and Abbreviations

If you’re mentioning a single letter or abbreviation and need to add a suffix, use an apostrophe. For example:

  • Don’t forget to dot your i’s and cross your t’s.
  • Practice writing your cursive k’s for homework!
  • The principal is OK’ing the decision to start a new art club at school.
  • According to the National Institute on Drug Abuse, more than 64,000 people OD’d in 2016.

Although you can also follow this rule for words like CD or VIP, it’s becoming more common to remove the apostrophe before the s. Therefore, you may see CDs instead of CD’s.

When NOT to Use an Apostrophe

You know that you should use an apostrophe to show possession. However, you should not use an apostrophe with possessive pronouns. This includes words like:

  • yours
  • hers
  • ours
  • theirs
  • its
  • mine

This can get a little confusing when you have contractions that look and sound like these possessive pronouns (its and it’s, who’s and whose, or your and you’re). One of the simplest ways to figure out whether or not to include an apostrophe is to determine if the word is a contraction. Reread your sentence with the full words rather than the contraction:

    Incorrect: The dog knocked over it’s water bowl.
    Correct: The dog knocked over its water bowl.

Since you can’t replace “its” with “it is”, you should use the possessive pronoun.

    Incorrect: Your an irreplaceable member of our team.
    Correct: You’re an irreplaceable member of our team.

However, by replacing “your” with “you are”, it becomes apparent that you should use a contraction with an apostrophe in the second example.

When to Use an Apostrophe: Conclusion

The most common instances for when to use an apostrophe are writing contractions or showing possession. Learning how to use apostrophes correctly will positively impact your writing by clarifying the ideas for your reader.

P.S. Become a better writer. Find out more here.


  • Jamie Goodwin

    Jamie graduated from Brigham Young University- Idaho with a degree in English Education. She spent several years teaching and tutoring students at the elementary, high school, and college level. She currently works as a contract writer and curriculum developer for online education courses. In her free time, she enjoys running and spending time with her boys!

One Response to When to Use an Apostrophe in Your Writing

  1. A Clarification on Years April 24, 2021 at 3:42 pm #

    1960’s is not incorrect, it’s just a little old fashioned. At least into the 1980s, the basic rule taught to US schoolchildren was to use an ‘s when indicating the plurals of letters and numerals. The rule was not limited to single letters. Under this convention, examples like “I own over 200 LP’s” or “Famous 14’s include Ernie Banks and Pete Rose” are correct.

    The “rule” that the examples I’ve given are incorrect arose over the past 35 or so because (a) computerized fonts allowed writers more flexibility in handling letters and numerals and (b) some grammar Nazis equate the older convention with the visually similar greengrocer’s apostrophe. Yes, it’s a little confusing that “1960’s” could be plural (“decade of the 1960’s”) or possessive (“1960’s Kentucky Derby winner was Venetian Way”). But many things in the English language are confusing.

    I prefer the new style and have switched to it over the course of my adulthood, but the old style isn’t wrong. It’s just old fashioned. And yes, it looks weird if you write “the decade of the ’60’s.”

    correct: decade of the 1960s
    also correct, although a little old fashioned: decade of the 1960’s
    incorrect: The greengrocer reduced prices on apple’s and pear’s.

    If you want to die on the apostrophes-and-numerals hill, start correcting the increasing majority of Americans who now abbreviate, for example, 1987 as 87’. People, that means 87 feet or 87 minutes, not 1987.

Magoosh blog comment policy: To create the best experience for our readers, we will only approve comments that are relevant to the article, general enough to be helpful to other students, concise, and well-written! 😄 Due to the high volume of comments across all of our blogs, we cannot promise that all comments will receive responses from our instructors.

We highly encourage students to help each other out and respond to other students' comments if you can!

If you are a Premium Magoosh student and would like more personalized service from our instructors, you can use the Help tab on the Magoosh dashboard. Thanks!

Leave a Reply