by Jennifer Walker

Created on: July 20, 2008   Last Updated: March 18, 2009

How to use apostrophes is something many people struggle with. Mis-use of it appears in the writings of my co-workers, on signs in front of businesses, even in newspaper and magazine articles. It's rampant in online discussion forums, which can be really distracting! Once you have an understanding of where apostrophes go and why, you will be able to use them correctly all the time. Here's a little primer to help you decide when (or when not) to use an apostrophe.

Apostrophes are used for three basic reasons: to indicate possessive, to replace missing letters or numbers, and to show plurals of lower case letters only.

Possessive

The possessive form of a noun is used to show ownership, such as "Mike's car" or "the girl's bicycle." However, this is not used when clarifying or describing an object, such as "bicycle tire." The tire doesn't really belong to the tire in this sense; it's a part of the bicycle. However, if you were to say, "That bicycle's tire is flat," you are referring to a particular part of that particular bicycle and you would use the possessive form. Time can also be possessive: "Three hours' wait" refers to the wait of three hours. However the word 'hours' in "I waited for three hours" is plural, not possessive.

Now that you know when to use the possessive form, you need to know how to use the apostrophe correctly! Basically, if the noun is singular, such as "Shelly" or "man," put an apostrophe and then the 's.' This includes singular nouns that end in 's.'

-Shelly's sweater is pretty. -The man's hat blew away. -James's cat needs to go outside.

When showing the possessive of a plural noun, you have two options: if the plural noun does not end in 's,' add an apostrophe, then the 's.' if the plural noun does end in 's,' add the apostrophe after the existing 's' and do not add another one.

-The women's restroom is closed. -The dogs' houses need to be cleaned.

Some words are already possessive and do not require an apostrophe, such as "his," "her," and "its." A common error is to use an apostrophe in the possessive form of "its," but this is not correct. "Its" is the possessive form of "it," just like "his" is the possessive form of "he." "It's" is a contraction for "it is."

-That hat is hers. -His pony is cute. -Its color is blue. -Your bike is over there.

Missing letters or numbers

Contractions are used in casual writing or speech to combine two words into one. The apostrophe shows that there are missing letters.

-I wouldn't do that if I were you. (would not) -It's too late to go out now. (it is) -You're right on time. (you are-"your" is possessive) -I should've called you. (should have) [Note: some people spell out "should've" incorrectly, such as "I should of called." What does "should of" mean? You should HAVE called. "Have" is a helping verb, indicating necessity. "Of" is a preposition. However, I digress.]

Years are often abbreviated, and an apostrophe would be used for the missing numbers, such as "The '08 election."

Plurals

Apostrophes are not used every time there is an 's' at the end of a word, nor for plurals of whole words, which are the most common mistakes that I see. The only time an apostrophe should be used in a plural is with lower case letters when they are discussed by themselves to improve readability. Capital letters, numbers, and symbols do not need apostrophes, although this is a fairly common practice and many editors like to use them.

-Mississippi has a lot of s's. -The typewriter is not making capital Ms. -You should not use &s in business writing.

Once you understand the rules for using apostrophes, you will know how to use them properly. Your readers will thank you! Best of luck and happy grammar!

Learn more about this author, Jennifer Walker.
Click here to send this author comments or questions.