17
Apostrophes
An apostrophe (’) has three functions: to show ownership or possession, to indicate omitted letters in contractions, and to form some plurals.
17a Use an apostrophe to indicate possession or ownership
Add -’s to make a singular noun possessive, including nouns that end with s or the sound of s and indefinite pronouns (anyone, nobody).
Note that the possessive forms of personal pronouns do not take apostrophes: mine, yours, his, hers, ours, theirs, its.
The possessive form of who is whose (not who’s).
Add an apostrophe to a plural noun to make it possessive, or add -’s if the plural noun does not end in s.
To show individual possession by two or more people or groups, add an apostrophe or -’s to each noun.
Sam works for two different teams.
To show joint possession by two people or groups, add an apostrophe or -’s to the last noun.
Add -’s to the last word of a compound noun to show possession.
17b Use an apostrophe to indicate the omitted letter or letters in a contraction
17c Use an apostrophe to form the plural of a number, letter, symbol, abbreviation, or word treated as a word
In the sentences above, note that numbers, letters, and words used as themselves are in italics. The -s ending should not be italicized, however. (For more on italics and underlining, see Section 23.)
When referring to the years in a decade, no apostrophe is used.
Apostrophes are used to signal the omission of the numerals that indicate the century.
the class of ’03 | music of the ’90s |
17d Avoid using apostrophes to form plurals and to form possessives for personal pronouns