Apostrophe Rules and Punctuation Guide With Examples

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Danielle McLeod

Danielle McLeod is a highly qualified secondary English Language Arts Instructor who brings a diverse educational background to her classroom. With degrees in science, English, and literacy, she has worked to create cross-curricular materials to bridge learning gaps and help students focus on effective writing and speech techniques. Currently working as a dual credit technical writing instructor at a Career and Technical Education Center, her curriculum development surrounds student focus on effective communication for future career choices.

The rules of the apostrophe are reasonably straightforward, yet they are misused quite often. This is because they are confused with other punctuation rules, making their use seem tricky. However, apostrophe usage can easily be remembered if you make a note of 2 basic things: apostrophes indicate possession, and apostrophes indicate contractions. 

If you can remember these two rules, you can make sure your writing uses the apostrophe punctuation mark correctly to bring concise, clear meaning to your writing. 

What is an Apostrophe?

An apostrophe is a punctuation mark specifically used to show possession or create a contraction. On a rare occasion, it can be used to provide a plural form of a noun in the shape of lowercase letters. 

Rules for Apostrophe Use

Apostrophes exist to serve two essential punctuation functions: to show possession and to indicate the omission of letters in words to form contractions. DO NOT use it to create plurals except in one notable exception mentioned below. 

Apostrophes and Possession

The apostrophe use of possession is often the most confusing rule to master simply because various style guides may provide more than one way to use the punctuation mark. Keep a few things in mind to help you decide the best way to use an apostrophe for possession. 

Use an apostrophe + -s at the end of a noun to show singular possession of something. 

For Example:

  • John’s baseball bat
  • Sarah’s dance class
  • Michael’s car

Some style guides suggest you do not add an extra -s to the end of a singular name that already ends in -s. It is entirely appropriate to add another -s to create the possessive form, but it is also acceptable to simply add the apostrophe. Choose which you are most comfortable with. Just be consistent through your writing once you choose one. 

For Example: 

  • Carlos’s new sneakers OR
  • Carlos’ new sneakers

The same rules apply to plural nouns to help show possession. Use an apostrophe + -s after a plural noun. But, only use an apostrophe after the -s at the end of a plural noun that ends in an -s. The additional -s are never needed with plural possession. 

For Example:

  • The children’s bedroom
  • The twins’ bedroom
  • The Clements’ new house
  • The Blackmans’ new house

Apostrophes and Joint Possession

First, you need to determine if you are indicating that two people own the same item together or if each individual owns separate versions of the same thing. Otherwise, apostrophe use can get a little tricky. 

If two people jointly own the same item together, you only add the possessive apostrophe + -s following the abovementioned rules to the final person listed. This indicates that both people jointly own the item.

For Example: 

  • John and Jenny’s vacation
  • Tim and Danielle’s new house
  • Wyatt and Ross’ fuzzy puppy

If you want to indicate that two people separately own versions of the same type of item, you must make both owners possessive. In this situation, make your items plural to indicate two separate entities. Again, you follow the same rules explained above. 

For Example:

  • John’s and Jenny’s vacation
  • Tim’s and Danielle’s new homes
  • Wyatt’s and Ross’ fuzzy puppies 

Apostrophes and Contractions

A contraction is two words combined to form one word that means the same thing. It is usually an informal use and requires the use of an apostrophe to designate where the letters you removed belong. Essentially, the apostrophe replaces the missing letters. 

For Example:

  • They + are = They’re
  • It + is = It’s
  • Is + not = Isn’t
  • We + are = We’re
  • They + will = They’ll 

Apostrophes and Plurals

Some people mistakenly believe that an apostrophe creates plurals. DO NOT do this unless you are explicitly using the plural form of lowercase letters. This is the ONLY notable exception to this rule. 

For Example:

  • Bullet: two l’s are used in the spelling of bullet.
  • Don’t forget to cross your t’s and dot your i’s.

How NOT to Use Apostrophes

Some of the confusion people have with using apostrophes stems from misuse or misunderstanding of the rules. Look at some common mistakes to understand how you should never use apostrophes to avoid confusion with your writing. 

DO NOT Use Apostrophes With Pronouns to Show Possession

Pronouns show possession without apostrophe use. For example: hers, his, mine, whose, theirs, yours, etc. 

DO NOT Create Double or Triple S’s

This is a tricky rule because you can add a second -s to proper names to show possession, but occasionally it sounds incorrect and creates difficulty in pronunciation. If it sounds the same with an apostrophe + -s as it does just with an apostrophe, you can add the extra -s.

For Example:

  • DO: Ross’ or Ross’s
  • DO: James’ or James’s
  • DON’T: Smiths’s
  • DON’T: Bosses’s

DO NOT Use Apostrophes To Signify Plural Nouns

Do not use an apostrophe to pluralize nouns unless you need to establish possession. 

For Example (incorrect): 

  • The student’s all went to the theme park for the end of the year trip. 

Remove the apostrophe to establish pluralization of the word student. 

For Example (correct):

  • The students all went to the theme park for the end of the year trip.

DO NOT Use Apostrophes For Uppercase Letters and Numbers Used as Nouns

When letters and numbers are used as nouns, avoid using apostrophes with them in a sentence. 

For Example (incorrect):

  • She received all A’s and B’s on her report card. 
  • I only have a stack of 20’s for change. 

Remove the apostrophe to establish pluralization of the letters and numbers. 

For Example (correct):

  • She received all As and Bs on her report card. 
  • I only have a stack of 20s for change. 

DO NOT Use Apostrophes For Abbreviations

Unless you are establishing ownership, avoid using apostrophes with abbreviations. 

For Example (incorrect): 

  • The CEO’s met to discuss their fiscal financial responsibilities. 

Remove the apostrophe to establish pluralization of the abbreviation. 

For Example (correct):

  • The CEOs met to discuss their fiscal financial responsibilities. 

Let’s Review

Apostrophes work to create ownership of an item or to create contractions. Although they can be used to signify the pluralization of lowercase letters, it is not allowed in any other context. Look back over the rules to remember when you can add an -s and when it is best to.