The apostrophe is the punctuation mark used in English to show possession or mark a contraction such as “don’t.”
In “don’t,” the apostrophe signals that letters have been omitted from “do not.” The same mark appears in possessive forms such as “the teacher’s desk” or “the dogs’ bowls,” although possession can also describe relationships rather than literal ownership, as in “today’s weather.”
A common mix-up is “it’s” versus “its.” “It’s” is a contraction of “it is” or “it has,” while “its” is the possessive pronoun and does not take an apostrophe. Possessive pronouns such as “hers,” “theirs,” “whose,” and “yours” also omit it.
The word apostrophe comes through French and Latin from Greek. In modern English, it is also used in a few plural forms, such as “mind your p’s and q’s,” though that usage is less common than its roles in contractions and possessives.