An apostrophe (‘) is a frequently used punctuation mark. Apostrophes are sometimes used incorrectly. Incorrect use may be related to teachings that do not fully explain how apostrophes should be used. We aim to help you understand how to use an apostrophe, with examples of correct (and incorrect) sentences containing this punctuation mark.

Apostrophes may be used when:
- A letter (or sometimes small series of letters) is omitted when a word is abbreviated (shortened).
- Before an ‘s’ when the words after the word with the ‘s’ at the end of it describe an object that belongs to the person or organization referred to. This is where a possessive is formed.
- After an ‘s’ at the end of a pleural word that already ends with an ‘s’ when the word after is an object that belongs to the word before. This is another example of where a possessive is formed.
- When a phrase, sentence, paragraph, or other excerpt is referenced from a third-party source when contained within a quote.
- A general reference to a letter, number, word, or phrase, that would be out of context if it was not separated from the rest of the sentence. We have already used an apostrophe in this way when we separated ‘s’ in points 2. and 3. above.
- Apostrophes Used in Abbreviations
Abbreviations that use apostrophes include: don’t (abbreviated form of do not), can’t (abbreviated form of cannot), it’s (abbreviated form of it is or it has), and they’re (abbreviated form of they are).
An apostrophe can also be used in this way when writing a spoken word that is pronounced incorrectly due to a person’s dialect or laziness of speech. Examples include goin’ for the word going, and travellin’ for the word travelling. The use of an apostrophe in this way would not be correct English unless it was specifically referring to the way a word is or has been spoken.
The general rule when writing a professional or academic document that does not refer to speech, and does not have the need to convey a message in a particular manner to engage the reader, is that the words should be written completely. Abbreviations should usually be avoided when the document is professional in nature e.g. policy documents and academic research papers.
- Apostrophes to Depict a Tangible or Intangible Possession that Belongs to Someone or Something (where an apostrophe is used to form a possessive)
Then something belongs to someone, or is something that is a component of an object/organization, an apostrophe is used before an ‘s’ at the end of the word, or just after the ‘s’ if the word already ends with an ‘s’.
This is easier to explain with examples:
- Robert’s shoes – The shoes belong to Robert
- Racheal’s left arm – The left arm of the person named Rachael
- The football club’s crest – The crest of the football club
- The building’s chimney – The chimney that is on that particular building
- The GP’s stethoscope – The stethoscope that belongs to the specific GP in question
- Apostrophes used at the end of a word ending in ‘s’, where the word is a plural of something, in order to form possessives
Just as in Section 2, this is where the apostrophe is used to denote a possession of someone or something. This time the apostrophe is used, but because the word already ends in an ‘s’, a second ‘s’ is not needed (it would sound strange in speech too).
Examples:
The United States’ flag – The flag (in this case the famous stars and stripes) of the USA. Note that this is an example of where an apostrophe is used at the end of a word that already ends in ‘s’. The United States’ flag is a correct sentence, whereas The United States’s flag would be an incorrect use of an apostrophe.
The Laguna Hills’ Police Department – The police department located in Laguna Hills.
- An Apostrophe Used to Show a Reference to some other document or speech i.e. a quote, within a quote.
In written text, you will often see a quote. A quote is usually shown by using speech marks before and after the quote.
Speech marks are double inverted commas (“), apostrophes are single inverted commas (‘).
A speech mark will be used at both the beginning and the end of a quotation i.e. “The quoted text, including all punctuation within the quote such as the full stop at the end of the sentence if the quote is a complete sentence.”
When speech marks are used for a quote, all other punctuation relating to that quote should be within the speech marks. If the quote is a sentence, the ending will be:
last words.”
not
last words”.
An example of a quote:
The Policeman stated, “You must slow down when driving in a residential area.”
A quote within a quote could be:
The Policeman stated, “I know that you were traveling too fast because my superintendent publically said ‘Spooner Avenue is now a 20mph zone’ just last week.”
In the above sentence, we have referenced the statement made by a police officer in attendance, who in turn referenced a third party (their superintendent) statement that they have heard during the primary reference statement.
When is it Incorrect to Use an Apostrophe?
American English differs from UK English sometimes. The conventional use of an apostrophe in different countries may vary.
We have already mentioned that a GP’s stethoscope is the stethoscope belonging to one particular GP.
When there are several GPs, an apostrophe is not needed because the term ‘GPs’ in this instance refers to a collective group of general practitioners rather than something that belongs to a specific general practitioner.
Note that the following sentences are correct:
The general practitioner’s stethoscope. This sentence describes the stethoscope belonging to an individual general practitioner.
The general practitioners all own equipment necessary for their jobs, including stethoscopes. Here ‘general practitioners’ relates to a group of general practitioners and not something belonging to an individual.
In Section 1, we stated that it’s is an abbreviation of it is, or it has. The term it’s can often be confused because people relate the use of an apostrophe in this context to a possessive term (something belonging to) rather than the omission of letters.
Example sentences:
The dog is in its kennel. Note here that the kennel belongs to the dog, but ‘its’ is correct rather than ‘it’s’ because the word before the ‘s’ is not the person or thing that the object belongs to. In this instance, if it’s was used, the sentence meaning would be changed to: The dog is in it is kennel, which is obviously incorrect English. If you want to use an apostrophe to denote that the kennel belongs to one specific dog, the sentence to use would be: The dog’s kennel.
We hope that this article has helped you understand how to use an apostrophe and when they should not be used. Note that there are differences in the accepted use of punctuation in different parts of the world where English is spoken. Always ask a suitable person for their advice on the correct use of punctuation, including apostrophes, in the region that you are intending that your writing will be read. You may also find other articles on this website that help you to write correctly with grammatically accurate use of punctuation, and precise spelling.
- The use of an Apostrophe to Separate a Character, Word, or Phrase
The use of an apostrophe to separate a character (letter or number), word, or phrase, has been done throughout this article. Alternative methods could be to italicise the text that needs to be separated. For most documents, we think that either method would be fine.
External References That You May Find Helpful
The definition of ‘Apostrophe’ from the Cambridge Dictionary