Apostrophes (’)

The apostrophe is a punctuation mark that serves three purposes: (1) to form a contraction, (2) to form the possessive case of a noun, and (3) to form the plural of an individual character. It is one of the most frequently misused punctuation marks because many contractions have the same pronunciation as unrelated possessives (e.g., “you’re” and “your”).

1.Using Possessive Apostrophes with Singular Nouns
2.Using Possessive Apostrophes with Plural Nouns
3.Apostrophes with Possessive Pronouns
4.Apostrophes with Multiple Possessives
5.Apostrophes with Contractions
6.Apostrophes and Plurals
7.Apostrophes and Surrounding Punctuation
8.Possessive Pronouns vs. Contractions

Using Possessive Apostrophes with Singular Nouns

The most common use of apostrophes in academic writing is to indicate possession. For a singular noun, the possessive apostrophe goes before the “s.”

Example: The sample’s consistency was too thin.

Possessive apostrophes can also be used with parenthetical citations in academic text. The proper way to do this depends on the academic field as well as journal and style guidelines. However, the following examples will demonstrate what is typically accepted.

Example: The analysis of Mercer et al. (2013) implies…

Incorrect: Mercer et al. (2013)’s analysis implies…

Correct: Mercer et al.’s (2013) analysis implies…

Using Possessive Apostrophes with Plural Nouns

For plural nouns that end in “s,” the possessive apostrophe goes after the “s.”

Incorrect: The sample’s consistencies were too thin.

Correct: The samples’ consistencies were too thin.

However, for plural nouns that do not end in “s,” the possessive apostrophe goes between the last letter and the added “s.”

Incorrect: The mices’ primary food source was found to be grass seeds.

Incorrect: The mice’ primary food source was found to be grass seeds.

Correct: The mice’s primary food source was found to be grass seeds.

Apostrophes with Possessive Pronouns

Unlike regular nouns, pronouns have possessive forms that do not involve the use of apostrophes. For example, the possessive form of the pronoun “him” is “his.”

Incorrect: He’s car is a blue Mini Cooper.

Correct: His car is a blue Mini Cooper.

Pronoun forms

	Pronoun as Subject	Possessive Pronouns	Possessive Adjectives
First Person	I We	Mine Ours	My Our
Second Person	You	Yours	Your
Third Person	He She It They	His Hers Its Theirs	His Her Its Their

Apostrophes with Multiple Possessives

When it is necessary to indicate the joint possession of a single item for multiple nouns, only the final noun is written in possessive form.

Incorrect: The mouse’s and the hamster’s carrot was grown in the campus greenhouse.

Correct: The mouse and hamster’s carrot was grown in the campus greenhouse.

However, to indicate the distinct possession of multiple items for multiple nouns, all the nouns are written in possessive form.

Incorrect: Miller’s and Matthew’s publishing houses are both searching for new and emerging authors.

Correct: Miller and Matthew’s publishing houses are both searching for new and emerging authors.

Apostrophes with Contractions

A contraction is a shortened version of a word or words. The apostrophe in a contraction is placed in the location of omitted letters. Contractions are generally not used in academic writing. However, they are used frequently in colloquial speech and more casual texts.

Without Contraction: Eva does not have a pen.

With Contraction: Eva doesn’t have a pen.

Without Contraction: I have got a pen.

With Contraction: I’ve got a pen.

“Doesn’t” is a contraction of “does not,” and the apostrophe is placed where the “o” in “not” has been omitted. “I’ve” is a contraction of “I have,” and the apostrophe is placed where the “h” and “a” in “have” have been omitted.

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Apostrophes and Plurals

Using an apostrophe to pluralize a noun is a common error. Typically, apostrophes cannot be used to pluralize nouns.

Incorrect: The book’s are not arranged properly.

Correct: The books are not arranged properly.

Apostrophes and Surrounding Punctuation

An apostrophe is a part of a given word or contraction. As such, it should not be separated from the word or contraction by a space or another punctuation mark.

Incorrect: “The cats’,” she began, then stopped, distracted by a robin chirping outside.

Correct: “The cats,’” she began, then stopped, distracted by a robin chirping outside.

Separating an apostrophe from the word or within the contraction with a space can also cause the apostrophe to display backwards in a word processor. (‘)

Incorrect: The cat‘s bowl is blue.

Correct: The cat’s bowl is blue.

Possessive Pronouns vs. Contractions

Many possessives and contractions have similar pronunciations. For example, the possessive “its” and the contraction “it’s” share the same pronunciation. The same applies to “their” and “they’re” as well as “your” and “you’re.”

This confusion can be avoided by keeping in mind what the contraction is short for. It is easy to confuse “whose” and “who’s.”

Incorrect: Its Courtney’s birthday.

Correct: It’s Courtney’s birthday.

Incorrect: They’re car is parked outside.

Correct: Their car is parked outside.

Incorrect: Your expected at the courthouse in five days.

Correct: You’re expected at the courthouse in five days.

Incorrect: Whose the man standing outside?

Correct: Who’s the man standing outside?