# What Are Possessive Nouns?  URL:: https://www.grammarly.com/blog/possessive-nouns/ Author:: grammarly.com ## Highlights > Plural nouns ending in an s simply take an apostrophe at the end to form a possessive noun > In most cases, a possessive noun is formed by adding an apostrophe +s to the noun, or if the noun is plural and already ends in s, only an apostrophe needs to be added > When a noun ends in the letter s or an s sound, the same format applies. This is a matter of style, however, and some style guides suggest leaving off the extra s. > I have been invited to the boss’s house for dinner. > The trainer flipped a fish into the walrus’s open mouth. --- Title: What Are Possessive Nouns? Author: grammarly.com Tags: readwise, articles date: 2024-01-30 --- # What Are Possessive Nouns?  URL:: https://www.grammarly.com/blog/possessive-nouns/ Author:: grammarly.com ## AI-Generated Summary None ## Highlights > Plural nouns ending in an s simply take an apostrophe at the end to form a possessive noun > In most cases, a possessive noun is formed by adding an apostrophe +s to the noun, or if the noun is plural and already ends in s, only an apostrophe needs to be added > When a noun ends in the letter s or an s sound, the same format applies. This is a matter of style, however, and some style guides suggest leaving off the extra s. > I have been invited to the boss’s house for dinner. > The trainer flipped a fish into the walrus’s open mouth.