First, there are languages where the apparent complementizer — 'that', in English — is not homophonic with a demonstrative. |
Thus, Clements reports that in Ewe all logophoric constructions contain the complementizer be. |
The relative pronoun could be homophonous with a complementizer, and this complementizer could cause mutation while the relative pronoun did not. |
There is no need, at least not without other assumptions, that the apparent complementizer itself function as a demonstrative. |
And even if there is a need for the complementizer itself to function as a demonstrative, there is no need for it to be a demonstrative. |
In many logophoric languages, a complementizer of this kind does seem to play an important role in logophoric marking. |