Possessives and Attributives

Q. A friend and I were looking at a poster that read “guys apartment.” I believe it should read “guys’ apartment.” She claims that it should read “guys’s apartment” and that the CMOS specifically gives the example of “guys’s” to make “guys” possessive. I looked through every section on possessives and did not find the word “guys’s” or any rule that would make this correct. Some people say “you guys’s apartment”—did I overlook the word “guys’s” as used in the attributive position? (I don’t think I did.)

A. “Guys’s” is acceptable in the way that “youse guys” is acceptable; that is, neither is yet recognized as standard prose, and if your friend can find it in CMOS, I’ll eat my hat. Plural nouns that end in s (like “guys”) don’t add another s to form the possessive, e.g., the students’ lounge. “Guys’ apartment” is the standard spelling. If you want to make “guys” attributive, you can get away without the apostrophe, but you might test the idea with a plural noun that doesn’t end in s to see whether the attributive actually works: I doubt you’d write “the women apartment,” so you shouldn’t write “the guys apartment” either. And shame on your friend. It must make you wonder what else she’s capable of.