vIt
is hard to determine the reasons for choice of s- or z- in this position. However;
v
v1.
Where the stem ends in a consonant or nasal, -s is chosen. Thus rumsa, wursi
v2. Where C2 is –s-, the
affix will have z-
v3. Where the C2 is –r-,
the affix will have S-
v4. Where the stem is
CVV, the affix will have S-
v5. Where C2 is –j-, the
affix will have j-