What's the rule for using “who” or “whom”?
Please help me with the grammar here. An explanation would be extra nice, that way I can get it right myself next time.
"There were ten people, five of who/whom collected hats."
I understand that if the "who" is the object, it becomes "whom", and if it's the subject it stays "who". From this page (yeah I'm a dummy) However, I am confused by "five of who" - I expect it to be the subject of "collected", but it somehow references the "ten people" and that leaves me clueless.