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Apostrophes Rules

Published by at August 17th, 2021 , Revised On November 12, 2021

Apostrophes are one of the most commonly used types of punctuation in the English language. They serve two purposes:

Indicate a contraction – e.g., He’s conducting research.

Indicate possession – e.g., The researcher’s method of research.

When to Use Apostrophes?

Use a possessive apostrophe with abbreviations, plural nouns, and singular nouns.

Abbreviations and acronyms

  • In the last year, BITCOIN’s value increased dramatically.

Singular nouns

  • I am thankful for my colleagues’ support.
  • I recommend you visiting Emma’s parlor.

Plural nouns

  • I am just so grateful for my teachers’ continuous assistance.
  • The children’s room looked messy at the first look.

When Not to Use Apostrophes?

Do not use a possessive apostrophe with possessive pronouns or when pluralising decades, acronyms, and nouns.

Possessive pronouns

  • The lion flashes its gaze past the zebra.
  • Whose pen is this?

Plural decades

  • During the 1940s, the world fought an unforgettable war.
  • The 1950s saw the collapse of the Soviet Empire.

Plural acronyms

  • Many NGOs are operating in Yemen to help the needy.
  • The KPIs of the project were unclear.

Possessive nouns

  • The Muslims around the world celebrate two Eids every year.

Using Apostrophe for Contractions

Contractions aren’t encouraged in academic writing, so you should avoid using them in your paper. When an apostrophe is used for a contraction, it shows some letters have been removed. The most common contractions comprise modals, auxiliaries, or verbs attached to other words.

Contraction Examples

Contraction Uncontracted Examples
-n’t not Isn’t (is not), hasn’t (has not)
-‘re are They’re (they are), we’re (we are), you’re (you are)
-‘d had, would She’d (she had, she would), I’d (I had, I would)
-‘ll will We’ll (we will), you’ll (you will)
-‘s is He’s (he is), it’s (it is)
I’m I am
let’s let us

Contractions are mostly used in informal writing. If you are writing something formal like an academic paper, it’s better to avoid them altogether.

Using Apostrophe with Possessive Nouns

Possession apostrophes are frequently used in all types of writing, particularly when expressing abbreviations and plurals. The rules of apostrophes when forming possessives can cause the most confusion.

Apostrophes can be puzzling even for native English speakers. However, you can still master them by learning the basic rules of the apostrophe. Let’s take a closer look at how apostrophes work and the rules of their use.

The rules of apostrophes when forming possessive nouns depend on the type of noun you are making. The following rules of the thumb should be considered when making possessive nouns using apostrophes.

Using Apostrophes with Singular Nouns

Apostrophes are used to signpost a relationship. You can simply add an ‘s’ at the end of the singular noun you wish to indicate possession for. This rule applies to all types of singular nouns, including names and proper nouns.

  • The writer’s skills are amazing.
  • London’s landscape is beautiful.
  • Hollywood’s action movies have become more prevalent in recent times.
  • The researcher’s desk is very tidy.
  • The planet’s atmosphere is deteriorating at an alarming pace.

The rule for proper nouns is that they should end in ‘s’. MLA and APA, and several other style guides recommend following this rule.

  • Nicholas’s new car is fast.
  • Jones’s new clinic was exceptionally well-maintained.
  • Jesus’s life remains a topic of debate even after many centuries.

Some style guides allow the use of an apostrophe only when the additional ‘s’ would be uncomfortable to phonate aloud. If in doubt or when you do not have a style guide to follow, it is always best to use ‘s’. As long as you remain consistent in your use of the method you picked, you will be alright.

Note: When citing a source in an academic paper, make sure to attach the apostrophe to the author’s name instead of the in-text citation.

  • This argument is supported by Michael (2020)’s study.
  • This argument is supported by Michael’s (2020) study.

Using Apostrophes with Plural Nouns

For plural nouns, you should use only an apostrophe:

  • The cats’ (multiple cats) house is adorable.
  • The researchers’ (multiple researchers) desk is very tidy.
  • The jungle fire destroyed the beavers’ home.

For singular entities and proper nouns, consider applying this exact rule:

  • The United States’ covid-19 situation is alarming.
  • The Mr. and Mrs. Harrises’ garage is full of mind-blowing gadgets.

However, when the plural noun does not end in s, then end it with both an apostrophe and ‘s’ as you would for a singular noun:

  • The children’s room is a mess.
  • Pollen’s harmful effects are widely accepted.
  • The sheep’s leg got broken.

Apostrophes and Possessive Pronouns

The rule for personal pronouns is a little different.

Do not use apostrophes to form possessives when dealing with regular nouns. While most writers do not have a problem with possessive pronouns like our, his, her, mine, and my – other pronouns such as their, theirs, ours, its, hers, yours, and your, are often a cause of confusion.

The rule surrounding the relative possessive pronoun whose is also a little ambiguous for some writers. Avoid using an apostrophe with any of these forms. In some cases, using an apostrophe with a pronoun results in a contraction instead of a possessive.

  • Is this pen your’s?
  • Is this pen yours?
  • Is this company their’s?
  • Is this company theirs?
  • Man throws cat by it’s tail.
  • Man throws cat by its tail.

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Indefinite Pronouns

You can not use an apostrophe with indefinite pronouns such as anybody, somebody, something, someone.

  • This is someones plan.
  • This is someone’s plan.
  • This could be anybodys mischievous.
  • This could be anybody’s mischievous

Apostrophes with Joint Possession

How do you use an apostrophe when the things in consideration belong to more than one person? Well, the rule is elementary.

When one thing belongs to two or more people, attach an apostrophe only to the last name.

  • Sarah and Jay’s boutique is attracting a lot of customers (Sarah and Jay own the same boutique)
  • Emma and Peter’s classmates were happy to see them back at school (Both Emma and Peter are students of the same class)

However, when different things belong to different people, it is mandatory to make each name possessive.

  • Sarah’s and Jay’s boutiques are attracting a lot of customers (Sarah and Jay both own separate boutiques)
  • Emma’s and Peter’s classmates were happy to see them back at school (Emma and Peter have different classmates)

Forming Plurals with Apostrophes

The rule concerning the formation of plurals with apostrophes in the English language is simple and straightforward.

Do not use an apostrophe to form a plural.

  • David Beckham was the leading footballer of the 1990’s.
    • David Beckham was the leading footballer of the 1990s.

There is one exception to this rule, though: You can pluralize letters of the alphabet.

      • Cross the j’s and dot the k’s.

Surrounding Punctuation

Do not separate the apostrophe from the word it’s attached to by punctuations like question markscommas, or period.

      • Did he ask her somethin’? during their meeting?

Apostrophe Rules Summary

While confusion surrounds the rules of using apostrophes in English writing, the rules are straightforward to master. The one basic rule that you need to remember is that all possessives should end with an apostrophe and an ‘s’ at the end.

If a word already ends in ‘s’ then you only need to add an apostrophe. If the word does not end in ‘s,’ then you will need to add an apostrophe and an s.

The rule of contraction is also simple. When you use an apostrophe for contraction, you are replacing some letters in the word.

About Alvin Nicolas

Nicolas has a master's degree in literature and a PhD degree in statistics. He loves to write, cook and run. Nicolas is passionate about helping students at all levels.