In some instances, the meaning of a word or phrase can be completely changed by adding or eliminating an apostrophe. It becomes difficult for readers to distinguish between a plural and a possessive without properly editing errors in apostrophe usage. So learn how to use this important punctuation mark correctly.

1

Remember that apostrophes have three uses: to form possessive nouns; to indicate the omission of letters and to show the plural of lower case letters
2

Make a singular noun possessive by adding an apostrophe after the last letter and placing an "s" after the apostrophe. Some examples are "the cat's pajamas" and "the hamster's cage." If a singular noun ends in an "s," the "s" after the apostrophe may look awkward, but it is still added. For example, it would be "Mary Jones's book" and "the class's grades."
3

Indicate possession of a plural noun that ends in "s" by simply adding an apostrophe. For example, "the campers' tents" and "the two friends' promises." If the plural of a noun does not end in "s," then you must add the apostrophe and the "s" as in "the geese's eggs" and "the children's toys."
4

Learn that in a contraction, an apostrophe is used to show the omission of certain letters. So the apostrophe in the word "don't," which means "do not," indicates the omission of the letter "n." Some other examples: "they're" (omission of "a") and "could've" (omision of "ha").