In this paper, I provide an analysis of the clause structure of Bartangi, an Eastern Iranian language spoken in the Pamirs, which has a configurational clause structure and varying positions of agreement markers (second-position clitics and affixes) depending on tense. I show how an LrFG account can generalize the apparent variability from a regular, largely invariable c-structure. I also propose a modification to the mechanism of spanning in LrFG to account for irregular forms instantiating nonadjacent nodes.
Oleg Belyaev (Thu,) studied this question.