Who is the spirit who never speaks in A Christmas Carol?

The Ghost of Christmas Yet to Come did not speak to Scrooge. All the other spirits observed by Scrooge during his "education" were unaware of his presence and did not interact with him on any way. This includes the rich ghosts throwing money to the poor woman, the characters in the party at Scrooges early employer etc. The Spirits and Ghosts which did speak to Scrooge were Marley, The Ghost of Christmas past and the Ghost of Christmas Present.