The possessive case denotes ownership or possession. Add an apostrophe and -s to form the possessive of most singular nouns, including those that end in -s, and of indefinite pronouns (24d). The possessive forms of personal pronouns do not take apostrophes: mine, yours, his, hers, its, ours, theirs.

The bus’s fumes overpowered her.

George Lucas’s movies have been wildly popular.

Anyone’s guess is as good as mine.