the way Gollum speaks

Why does Gollum speak in plurals (hobbitses, orcses, when he says he to Deagol 'its my birthday and I /wants/ it' etc)

Is that purely the way he speaks anyway, or is it part of the rings effect on him, along with the physical things that happen?

EDIT: The thread 'why does Gollum refer to himself as we' was focused on why he used we when speaking, whether it's Gollum and Smeagol, or Gollum and the ring

I was asking about adding extra 'S' on the end of words that don't need it