Ok, if we still can't figure out the official rule after more than seven years of the world's greatest Ph.D. Grammar Tyrants arguing, I'm just going to assume the rule doesn't matter enough to really care. I'll just say "someone else's" and "passersby." Good enough. English is technically a second language for me anyway, so I have an excuse. Haha, just kidding... I actually speak English better than my first language now (Nynorsk).

Laurie, your post literally made me laugh out loud. I won't understand the world around me, and I won't be able to understand what I'm reading unless I've learned perfect English? Ummm, no, but thanks for the laugh! My skills in English were only so-so until my early 20s, but I understood my world and books quite well long before then, thank you! I am not trying to pretend my grammar is commendable, so I'm allowed to make mistakes, but you really should proofread what you write if you're going to be that pretentious and patronizing. (You made several errors.) Also, if language did not evolve, we would still be talking like Shakespeare. But hey, as long as you have that terrific view from the top of you high horse, what do you care?

Brockaway, eaglesight, Warsaw, mike, cosmic, and others brought up some very interesting points, and I do appreciate all of your thoughts. Thank you. But a few of you really need to relax :)

English is fun! (shoot me)