But none is more striking than the “correct” way to form possessives of singular nouns ending in S. Here, according to the Chicago Manual of Style, are three correct possessives: James’s ...

A possessive is a word that shows possession or ownership of something. A possessive can be a noun, pronoun or adjective. Nouns are usually made possessive by adding an apostrophe and an ‘s’.

A singular noun is a noun referring to just one person or thing, for example 'cat'. When you want to show that something belongs to that person or thing, you add a possessive apostrophe and an 's'.