Learning Objectives:

  • Identify appropriate use of apostrophes showing ownership or relationship.
  • Identify appropriate use of apostrophes used to shorten words.

In this lesson, you will learn how to use apostrophesA punctuation mark that has two uses. Apostrophes show where letters are taken out to make a contraction, as in shortening cannot to can't. Apostrophes also show possessive relationships between people or things. For example, the apostrophe in the phrase Emily's book means the book belongs to Emily. correctly. Apostrophes are only used in two situations. The first situation is when showing ownership or a close relationship between people or things. The second situation is when creating a contractionA word that is a shorter form of a longer word or group of words that is made by leaving out sounds and/or letters. Example: can't is a contraction for cannot. of two words. In this case, the apostrophe shows where a letter or letters have been taken out.


Here are examples of using an apostrophe to show ownership/possession or a relationship:

Whenever an apostrophe is used to show ownership or a relationship, the word ends in either – 's or –s'. Because of this, people often confuse pluralsA grammatical term that indicates more than one person, place, or thing is being described. Plural nouns often end in an -s. Example: The books are red. (which do not need an apostrophe) with possessivesIn grammar, possessive refers to words or forms that show ownership. These include nouns ending with 's or s' as in the phrases the dog's toy or both dogs' toys. There are also many possessive pronouns, for example my, mine, yours, ours, and theirs. (which do). To differentiate between the two, ask yourself if the word shows someone or something owning or having something.

For example:

If you can rearrange the sentence to fit into the construction "the ____ of _______," you are signifying possession, and you need an apostrophe. If not, the word is plural and does not require an apostrophe. The table below illustrates the difference between the two.



the professor's argument

the professors in the department

the organization's needs

the most influential organizations

our country's history

both countries in the study

by the semester's end

after two semesters

Once you determine that you need an apostrophe, you need to make sure that you put it in the right place. You have two options: an apostrophe before the –s ('s) or after the –s (s' ).

There is only one situation that calls for the apostrophe to come after the –s. That is when the person or object is a plural word that was made plural by adding an –s or –es.

For example:

In all other instances, the apostrophe comes before the –s when showing possession. This is true even with singular words and names that end in –s like Rufus or Jones. It may seem awkward to write Rufus's car and you may notice that some people omit the second -s, but it is clearer for the reader and always correct to include the complete –'s with such singular words and names. You will also use –'s for indefinite pronounsNouns that may sound plural but are always singular and require a singular verb. Examples: something, enough, nobody, everybody. like anyone and everybody and for words that are made plural without an –s.

For example:

The most common apostrophe mistake is probably it's and its. Keep in mind, it's is a contraction that always means it is. Also, since there is no plural form of the word it, its is the possessive form, even though it has no apostrophe.


A contraction is a shortened version of a word phrase. The apostrophe is used to indicate the missing letters. The most common apostrophes combine a nounA part of speech that refers to a person, place, or thing. Examples include: swimmer, lake, sunscreen. or pronounA part of speech that substitutes for a noun or noun phrase. Examples include: I, he, you, they. with a verbA part of speech that refers to what is happening, the action, what the subject is doing, or how it is “being.” Examples include: sleep, to be, think., like I've or Henry's for I have and Henry is, or nouns combined with the adverbWords that modify and describe a verb, adjective, or other adverb. Examples: quickly, awkwardly, lovingly. not, like can't and don't for cannot and do not. Here are some other examples:

Word phrase


I am


they are


let us


we will


does not


Remember that pronouns present special challenges and follow their own rules. There is a difference between a pronoun contraction and a pronoun that shows possession. Your shows possession; you're is a contraction that means you are. Similarly, their shows possession while they're is a contraction that means they are. The use of contractions is considered informal and is therefore discouraged in most academic writing. When in doubt, use the more formal approach and write out the entire word phrase.