apostrophes

An apostrophe is a punctuation mark used mainly to indicate possession, to form contractions, and to signal omitted letters. The name comes from the Greek apostrophos, meaning a sign of omission. In modern English, its primary functions are to show that something belongs to someone or something, to join words by omitting letters, and to indicate special plural forms in some cases.

For possession, add ’s to singular nouns: the dog’s bone. For plural nouns that already end in s, place only an apostrophe after the s: the dogs’ bone. For irregular plurals not ending in s, add ’s: the children’s playground. Possessive pronouns (its, hers, theirs, yours) do not use an apostrophe.

Apostrophes also mark contractions, where letters are omitted: it’s (it is), don’t (do not), you’re (you are). They can also indicate a omitted syllables or letters in dialect writing or in informal style, such as rock ’n’ roll or ’60s slang.

In addition, apostrophes may be used to pluralize single letters, numbers, and symbols to avoid ambiguity: p’s and q’s, mind your X’s and O’s, or the class of the 1990s written as ’90s in informal contexts. Some guides discourage or discourage certain uses, such as years written with a leading apostrophe, except in specific stylistic contexts.

Common points of confusion include its vs it’s and the possessive form of names ending in s, which may be written as s’s or just s’ depending on the style guide. The apostrophe is a versatile, sometimes controversial, mark in English punctuation.