How common are zero marked instruments/locations when cased forms also exist?

[jess tauber]

Hi again. As Yahgan is a differential case marking language one would expect there to be more than one object case mark. I'm finding, though, that the same may be true for instruments and locations. 

The zero-marked locations seem generally to be glossed as 'at', unless the verb sense shifts it away from this, while those with locative suffix -un/-an are mostly 'in'.

There seems to be a differentiation too between case-marked forms in -a:ki or -a, more generally instrumental in sense, versus the zero-marked forms, which have a broader semantic range of 'with, using' (such as ingredients, parts, etc. as well as instruments). The zero-marked forms appear to be more greatly affected by the verb semantics here as well.

Does this sort of thing seem familiar to any of you from the languages you've worked with? Thanks.

Jess Tauber
phonosemantics at earthlink.net