On the standard usage for the possessive of "Illinois" being "Illinois'" ending with an apostrophe, not an "s":

Undecided edit

  • Wikipedia's Wikipedia:Manual of Style#Possessives is contradictory, saying "Illinois's legislature" but then saying "For a singular noun ending in one s, there are two widely accepted forms". Also notes that there is still much debate about this.
  • Wikipedia's Apostrophe#Nouns ending with silent "s", "x", or "z" notes: The same principles and residual uncertainties apply with "naturalised" English words, like Illinois and Arkansas. — also has links to some sort-of-related discussions

Illinois' edit

Universities edit

State government works edit

Federal judicial works edit

  • U.S. Supreme Court — Jonathan Starbl, "Gimme an S", 10/9/2006, Legal Times, quoted in the Language Log: "Scalia repeatedly referred to the possessive of Illinois as Illinois' rather than Illinois's. He has also shown other inconsistencies, such as his repeated use of the word Congress', which is inexplicable in light of his acknowledgment of the word witness's in his Marsh concurrence and his use of the word Congress's in his 2004 majority opinion in Vieth v. Jubelirer."

Illinois's edit

Related edit

  • Merriam-Webster: Illinoisan \ˌi-lə-ˈnȯi-ən also -ˈnȯi-zən\ adjective or noun

References edit

  1. ^ a b Freeman, Jan (2007-03-04). "Possessed by punctuation". The Word. Boston, Massachusetts: Globe Newspaper Company. Retrieved 2019-06-05. Illinois' and Congress', as AP would do it. [...] The Chicago Manual of Style says it's Kansas's and boss's, but when a final sibilant is silent, you can switch to apostrophe-only style: Camus' depression, Francois' flirtation, Arkansas' solons.