Apostrophes indicate possessives and contractions

Picture: Printable alphabets

I. Apostrophes are used to INDICATE POSSESSION. They follow singular nouns, common or proper, coming before the s to form a singular possessive, as follows:


     The child's mother appeared at the door. (common noun)

     London's fame is indisputable. (proper nouns)

When the noun, whether proper or common, already ends in s, we have options. We may use 's or simply s', as shown below.

     Marcus's election was a surprise to many of us.

[The s's may be replaced with the 'of' possessive: The election of Marcus as president was a surprise.]

It is acceptable to write the possessive of a proper noun with or without the second s, as seen below:

    Morris's car broke down. [or Morris' car broke down.]


Technically, it is also correct to use an apostrophe alone after the plural s of a common noun to indicate that it is plural and possessive. However in general, these combination plural possessives are stylistically a bit awkward, and better avoided. (Use the of possessive instead.)

     We put away all the boys' belongings. (This refers to items belonging to more than one boy)
     We put away the belongings of all the boys. (alternative of possessive sounds better here)

[Note that the following sentences sound fine, because people and children are irregular plurals.]

     We put away the children's belongings.
     Marcus was the people's choice.

In the case of compound nouns, the 's comes at the end, like this:
     The five-year-old's shoes...
     The do-it-yourselfer's project...

Note that possessive pronouns (hers, theirs, its etc.) do NOT employ apostrophes.(exception: one's)

II. Apostrophes are also used TO JOIN CONTRACTIONS. Their presence indicates that letters have been omitted, as shown below:

    It's a long way to New York. (It is a long way...)
    He's been having health problems. (He has...)
    She's going home now. (She is...)
    We've nearly finished our meal. (We have...)

Apostrophes are NOT used to name decades with numbers, but they are used to talk about individual letters of the alphabet, as in dotting one's i's and crossing one's t's. (One is the only pronoun to be used with an apostrophe to show plural.)

For more information, read Jane Straus's list of rules and try her quiz, here.