I am a bit confused. Can you say: Can I stay at somebody who lives nearby? Or is it Can I stay at somebody's who lives nearby? I know another possibility is "Can I stay at somebody's house?", but what about the other two??
There is a possibility of "Could I stay at somebody's?" being OK. If a group of people are together and one says "I'm staying at John's house tonight" and someone else who currently has nowhere to stay thinks that another person in the group might be able to put them up for the night, they might say "Could I [also] stay at somebody's please?"
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.
Thanks so much!
Maybe "I stayed WITH somebody" would make some of these issues go away.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.