Possessive Errors

When you want to show ownership efficiently, use an apostrophe and an "s." For example you should not write:

the skateboard owned by Josh

Instead, you should write:

Josh's skateboard

When a noun ends in "s" and the addition of 's makes the word sound odd, some writers add only an apostrophe, as in this example:

Chris' lab report

In reviewing your work, be certain that you have used apostrophes where you need them. How should this sentence be corrected?

The instructors patience for noise waned by the end of the period.

Writers sometimes put the apostrophe in the wrong place. For example, in the following sentence the apostrophe should really be between the second "r" and the "s" in cheerleaders:

A cheerleaders' job is to draw the crowd into the game and encourage them to cheer.

You will only use a possessive word ending with an apostrophe if it is a plural noun:

The two boys' idea was to toilet paper the school, but the janitor caught the boys before they could start.

When two or more people share ownership, you use an apostrophe and "s" on the last noun (John and Jack's room). When each person has separate ownership, however, you need to indicate the separation. For example:

Ian's and George's ambitions are very different from each other and from the ambitions of most ten-year-old boys.

Possessive pronouns do not require an apostrophe.

His, hers, its, ours, yours, theirs, and whose are pronouns that already convey possession, and therefore do not need an apostrophe. This sentence is incorrect:

It was his' terrible idea to name the rat we had to dissect in biology class.

Do not use an apostrophe when you want to make a noun plural.

An apostrophe shows possession. It should never be used to show the plural form of a noun. For example:

Runner's on the cross-country team cheered wildly when their coach announced they were getting new uniform's.

This sentence should be corrected to read:

Runners on the cross-country team cheered wildly when their coach announced they were getting new uniforms.

Most stylebooks indicate that numbers, letters, and abbreviations do not require apostrophes to show plurals. Here are some examples:

My brother received all 5s on his advanced placement tests.

Registration for students whose names end in Rs, Ss, and Ts is underneath the clock.

My sister took the SATs twice before she was finally satisfied with her scores.

Proofread all the words with which you have used an apostrophe to check whether you used it correctly.