This thesis deals with differential indexing, i.e. intra-linguistic variation in bound
verbal person marking, and the referential and discourse-structural factors which
trigger it. Although the same underlying factors for differential indexing, such as
animacy and definitness, can be encountered again and again across languages,
the exact manifestation of these factors has to be viewed language-specifically.
Not only can languages differ with regard to the relevant factors themselves, but
also with regard to where a line is drawn on the respective hierarchies associated
with those factors, or whether there is a precise line to be drawn at all. Additionally,
if there is more than one factor identified as being involved in indexing, the extent
to which these impact or depend on one another remain to be determined. This
thesis comprises four articles, viz. three in-depth case studies on differential
indexing in the languages Ruuli (Bantu), Maltese (Semitic) and Gutob (Munda),
and one typologically informed discussion of the phenomenon, looking into
structural and functional differences and similarities of differential indexing for the
A as well as the P role.