Quote

General Rules for Forming Possessives Plural Common Nouns Ending in S AP and Chicago: Add an apostrophe—jinx! the students’ questions the teachers’ headaches Singular Common Nouns Ending in S AP: Add apostrophe-s unless the next word begins with s. the duchess’s hat the duchess’ style Chicago: Add apostrophe-s. the duchess’s hat the duchess’s style Proper Nouns Ending in S AP: Add an apostrophe. Charlaine Harris’ books the Joneses’ competition Chicago: Add apostrophe-s if singular, and add an apostrophe if plural. Socrates’s tea the Obamas’ garden Les’s moor Nouns Plural in Form, Singular in Meaning AP and Chicago: Add an apostrophe. the series’ actors the Academy of Motion Picture Arts and Sciences’ history Special Case: Nouns Ending in an Unpronounced S AP: Add an apostrophe. Descartes’ thoughts Chicago: Add apostrophe-s. Camus’s existence the debris’s cloud Special Case: Singular Common Nouns Ending in S or an S Sound, Followed by a Word Beginning With S AP: Add apostrophe. for appearance’ sake for conscience’ sake for goodness’ sake Chicago: Add an apostrophe if the word ends in s; otherwise, add apostrophe-s. for appearance’s sake for conscience’s sake for goodness’ sake Proper nouns ending in s follow previously stated styles (e.g., for Jesus’s sake in Chicago style). Exception: Company Names With Apostrophe-S AP: Use as is. McDonald’s profits (not McDonald’s’ profits) So, to answer the question posed in the beginning (Carlos’ stylebook or Carlos’s stylebook?), the first is in AP style, the second is in Chicago style. Let’s hope that Carlos picked the right stylebook. Sources AP, 2011: “apostrophe”; “Ask the Editor” CMOS, 16th edition: possessives, 7.15-21

⁠— Unknown