Why do we say "He hardly has any money ON him", instead of "...with him"? Good question! I am not sure of the answer to that apart from; it is just one of those funny things in English that do not make sense!

Great question. It is my experience as an English teacher and being raised in the U.S. that both sentences are used regularly. We can use those phrases for anything we carry with us that is typically concealed (in a pocket). "I don't have my wallet with me." "I don't have my wallet on me." "Dang, I can't read this menu. I don't have my glasses on/with me."

What do we say? (Who is for people) We can say both and they mean the same thing.