Possessivestyle

Possessivestyle refers to the conventions used in English and other languages for indicating possession in written text. It encompasses punctuation marks, possessive determiners, and the rules that govern how possession is shown across different word classes and grammatical contexts. In editing and typesetting, possessivestyle aims to produce clear, consistent marks of ownership that align with a chosen style guide or publisher preferences.

In punctuation, the most common device is the apostrophe-s ('s) to mark singular possession, as in the cat's whiskers. For plural nouns that are already pluralized with an -s, the possessive is typically formed by adding only an apostrophe after the existing s: the cats' whiskers. Irregular plurals that do not end in s are usually given with 's: the children's toys. For singular proper nouns ending in s, there is variation among style guides, with some preferring James's book and others James' book.

Possessive constructions with multiple owners or shared possession also follow conventions. For joint possession, the usual form is Marcus and Lisa's car to indicate one car shared by both; if each person has a separate item, you may write Marcus's car and Lisa's car or Marcus's and Lisa's cars, depending on the chosen style. Possessive determiners such as its, her, his, their, and your mark ownership without punctuation, but its vs it's is a common spelling and usage distinction: its is possessive, it's is the contraction of it is.

Style guides, publishers, and educational authorities vary in exact prescriptions, especially for names ending in s and for historical or literary names. Common references include the Chicago Manual of Style and Associated Press style, each outlining preferred practices for different contexts.

See also: genitive case, possessive determiner, apostrophe usage.