The Unified Monophthongization Rule of Common Slavic
Feldstein
The goal of this paper is to show that the Common Slavic monophthongization
of diphthongs was a much more uniform process than has been thought. There
are two main types of rules, depending on whether the two moraic components
of the diphthong have a pure sonority contrast (± consonantal or ± high)
or a sonority contrast in addition to one of nasality or front/back. In
the case of the pure sonority contrast, one of the input moras becomes
the moraic unit of the new two-mora monophthong. The question of whether
it is the first or second mora depends on the sonority distance between
the diphthongal components; in the unmarked case of lesser sonority distance,
the second component is generalized in the monophthong, but a greater
sonority distance causes the first component to become the moraic unit
of the monophthong. When the diphthongal contrast involves sonority plus
nasality or front/back, the non-nasal or back component first experiences
assimilation to nasality or frontness and then serves as the moraic model
for the resulting monophthong. These two basic rule types can be readily
applied to both glide and nasal diphthongs, with the proviso that non-high
vowels must be considered low (Š, a), rather than the
traditionally assumed mid vowels (e, o). However, in
the case of liquid diphthongs, there is an important difference of relative
chronology between southern and northern zones. Southern zones experience
the change of short vowels to mid only after the monophthongization of
liquid diphthongs, while the northern zones first undergo the change of
short vowel > mid, and only then monophthongize the liquid diphthongs.
The presence of unchanged low and high vowels (*tart and *turt)
accounts for the southern reflexes, while the new mid vowel combinations
of the North (*tort and *tərt) account for the northern
results. Thus, virtually all of the diphthongal reflexes of Slavic can
be explained by: 1) recognizing differing monophthongization rules for
pure sonority contrasts, as contrasted with sonority in combination with
nasality or front/back; and 2) recognizing the differing northern and
southern relative chronologies for monophthongization and short vowel
> mid in the last set of diphthongs to monophthongize, which are the
liquids.