Answer:
What is weightless but it needs two person to hold it?
If eleven plus two equals one, what is nine plus five equal to?
What is it that no man ever yet did see, which never was, but always is to be?
I know a word of letters three. Add two, and fewer there will be!
My first is nothing but a nameอพ my second is more smallอพ my whole is of so little fame it has no name at all.
What is yours but only used by others?