Apostrophes

Use an apostrophe to:

1. Indicate the possessive case of nouns. This is the most common use of the apostrophe.
2. Indicate omission of text, most often in contractions.
3. Indicate a plural noun form in rare cases.

Note: This resource assumes the reader has knowledge of the different types of nouns (e.g., singular, plural, common, proper). If you are unfamiliar with these terms, see our resource on Articles for definitions.

The possessive case indicates ownership or association. For most singular nouns, the possessive case is formed by adding an apostrophe + s to the end of the noun. Examples:

The dog’s tail wagged. (This means the same thing as The tail of the dog wagged.)

Sam’s homework was late. (This means the same thing as The homework of Sam was late.)

Louisiana’s capital is Baton Rouge. (This means the same thing as The capital of Louisiana is Baton Rouge.)


To form the possessive case of singular common nouns that end in s, add an apostrophe + s as you normally would (e.g., the boss’s report, the witness’s testimony). However, for proper nouns that end in s, you can either add an apostrophe + s or simply add s. Examples:

The New Testament discusses Jesus’s teachings.     OR       The New Testament discusses Jesus’ teachings.

Hercules’s strength was unmatched by men.           OR       Hercules’ strength was unmatched by men.


Note: While either of these methods is correct, be consistent in which one you use. In other words, pick a method and use the same method throughout your text.


The possessive case of pronouns do not use an apostrophe. Examples:

The dog wagged its tail.

That pizza on the table is ours.

Mine is right here. Yours is over there.

******************************************************************************************************


To form the possessive case of plural nouns that end in s, simply place an apostrophe after the s. Examples:

All three of the cats’ bowls were empty.

The friends’ meeting with each other went well.

Those two boys’ bikes are leaning against the wall.


To form the possessive case of plural nouns that do not end in s, add an apostrophe + s just as you would for a singular noun. Examples:

The children’s toys are on the counter.

He forgot to bring the men’s hats.

Who stole the mice’s cheese


******************************************************************************************************


For compound subjects and compound objects in which all the nouns possess the same thing, add an apostrophe + s to the last noun only. Examples:

Selma and Fadi’s house is beautiful. (The house of Selma and Fadi is beautiful—same house)

We went with Becky and Robin’s friend. (We went with the friend of Becky and Robin—same friend)

You need to fill the dog, cat, and bird’s dish. (You need to fill the dish of the dog, cat, and bird—same dish)


For compound subjects and compound objects in which the nouns possess different things, add an apostrophe + s to each noun. Examples:

Selma’s and Fadi’s houses are beautiful. (Selma’s house is beautiful and Fadi’s house is beautiful—different houses)

We went out with Becky’s and Robin’s friends. (We went out with Becky’s friend and Robin’s friend—different friends)

You need to fill the dog’s, cat’s, and bird’s dishes. (You need to fill the dog’s dish, the cat’s dish, and the bird’s dish—different dishes)

The most common reason to use an apostrophe to omit text is to form a contraction, a shortened version of a two-word phrase. Examples:

I do not have my homework becomes I don’t have my homework.

He could have done better becomes He could’ve done better.

It is my favorite book becomes It’s my favorite book.

Note 1: Contractions are considered markers of an informal tone, so avoid them if you are writing or speaking in a formal context.

Note 2: Be careful not to confuse its (the possessive pronoun) with it’s (the contraction for it is).


******************************************************************************************************


Apostrophes may also be used to omit letters in common phrases or numbers in years. Examples:

I love rock and roll becomes I love rock ‘n’ roll.

She graduated with the class of 2006 becomes She graduated with the class of ’06.

It’s twelve of the clock becomes It’s twelve o’clock.


 ******************************************************************************************************


Finally, apostrophes may be used to omit letters (usually the g at the end of words ending with –ing) to indicate colloquial language. Example:

She said, “I sure do love swimming” becomes She said, “I sure do love swimmin’.”

Note: Using the apostrophe in this way is considered informal and should only be used when quoting other people or when writing for entertainment purposes.

The only reason to use an apostrophe to form a plural noun is to eliminate ambiguity that would result if an apostrophe were not used. This almost always occurs in the rare instances when a single letter needs to be plural. Examples:

He received three A’s this year. (Without the apostrophe, A’s could be misread as the word as.)

We have two Group I’s and three Group U’s. (Without the apostrophes, I’s could be misread as the word is, and U’s could be misread as the word us.)

Accidentally misusing “it’s” or “its” may seem like a minor detail, but it changes the meaning of a phrase completely. “It’s” and “its” are used for different things, both of which are outlined below.

It’s

Purpose: A contraction form of “it is”: the comma shows a word has been taken out

Use: Writing genres where contractions are acceptable (typically non-academic or essay writing); when you want your writing to sound more conversational; when writing how someone would speak. Examples:

It’s pretty weather today. à It is pretty weather today.

I’m not sure if it’s a good idea. à I’m not sure if it is a good idea.

Its

Purpose: Possessive form of “it”; shows ownership of, or belonging to

Use: Indicating possession by a noun that is ungendered or gender may be unknown. Examples:

The bird showed off its personality.

That song left its mark.