Schegloff, E. A. (2004). On Dispensability. 
Research on Language and Social Interaction, 
37(2), 95-149.

I describe 5 sequential environments in which 
speakers produce talk designed to be, and to be 
recognizable as, “the same” as something 
previously said. Examination of such talk reveals
that such resayings may omit elements that 
occurred in the first saying — elements that are 
apparently taken to be dispensable in getting “the
same thing” said. On the other hand, some 
resayings add elements to the first saying — 
elements that were apparently dispensable on the 
first saying. In some resayings, both of these
occur. Finally, the treatment of possibly 
dispensable turn-initial markers—that is, reusing
them or dispensing with them—is shown to be a 
vehicle for achieving the reflexivity of position
and composition in conversation: The usage making
some position the currently relevant one and the 
currently relevant position making relevant the
usage that is employed.