Johnson 2004 - CDLI - UCLA

straightforward: the perception began at one location and ended up at another
location—both locations appearing in the same case, *-e. Since the two locations were
indicated, as locations, by the same postpositional morphology, namely *-e, the thematic
roles of the two locations must have been assigned by some other component of the
clause. This is where the *bi-, *ba-, *ni-, *na- system would have stepped in: the *bi- and
*ba- prefixes may have identified the topical (or, in an obviational system [see Aissen
1997 for a recent overview], the proximal) locative noun as a source, whereas the *ni-
and *na- prefixes identified the topical or proximal locative noun as a goal. Such a
scenario would also explain the fact that in later phases of the language *ba- indicated
movement away from speaker (if the proximal locative noun—proximal to speaker that
is—is a source, then the corresponding goal will necessarily represent movement away
from speaker), whereas the derived form *imma-√ indicates motion toward speaker. As
predicted by Nichols’ diachronic model (see above), the BNBV inal construction seems to
be the only part of the grammar in which the full system is preserved: the proximal
locative, gig.e in the paradigmatic example, is identified as the source of the perception,
while the non-proximal locative, en aratta ki .ke 4, by implication, must be the goal of the
perception. I would imagine that the *bi-, *ba-, *ni-, *na- system was formed through
grammaticalization of the set A deictics as low applicative heads, which originated as
auxiliary verbs in clause final position.
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