"Any" is for negative sentences (I don't want to meet anyone) or a general question (Does anyone speak Spanish?). "Some" is used in an affirmative way (There is someone at the door). Sometimes, they are interchangeable. I don't think there's a difference between "no one" and "nobody" This may just make it more confusing...but read for yourself! http://www.netjeff.com/humor/item.cgi?file=EverybodiesJob