2.10 Phonologically significant phoneme classes.

We here mention briefly some ways in which the phonological rules of Chapter 3, accounting for alternations in paradigms and derivations, provide evidence for phonologically (not just phonetically) operative classes of phonemes.

Not much can be said of vowels since there are not many relevant rules, especially if minor length alternations are omitted. A high vs. low opposition seems apparent in the environment for V-Truncation P-46 (§3.47), since /u i/ diverge from /a/. However, in the more significant VV-Contraction P-49 (§3.50), the most productive subrules seem to show a scalar dominance hierarchy /i > u > a/, with several local complications.

Most rules involve consonants. Hardening P-18 (§3.19) and some other rules such as Lenition P-16 (§3.17) point to the phonological significance of paired continuants on the other, as already noted in §2.5. The latter group is noteworthy since /w2 w1 1h r r y/ is not a natural class phonetically (since /1 1/ are omitted). The category of stops is also needed in some other rules such as ngu-Epenthesis P-1 (§3.2), Initial Reduplication P-2 (§3.3), and Nasal-Assimilation P-27 (§3.28), and is obviously a major phonological class. A residual class of non-stops, namely nasals, liquids, and semivowels (i.e., sonorants and vowels.

However, a different division is needed in the conditioning environment for Hardening P-18 (§3.19). This rule requires that the final consonant of the preceding morpheme be a nonnasal sonorants (plus vowels). There are also rules by which stops are converted into nasals or vice-versa (Nasalisation P-22 §3.23, Denasalisation P-23 §3.24), and rules deleting stops (Stop-Deletion P-29 §3.30) and nasals (Nasal-Deletion P-30 §3.31) are roughly parallel. The class of Semivowels are a class in Initial Semivowel-Insertion P-5 (§3.6), and both /w/ and /y/ get dropped in roughly similar environments in the irregular alternations dealt with by Homorganic Semivowel-Deletion P-4 (§3.5). However, other rules apply to /w1/, /w2/ and /y/ in distinctive ways.

Point-of-articulation classes are relevant with reference to the output constraints dealt with above in this chapter, such as the absence of labials in the same positions except for verbal root forms (§12.2) and a few marginal items. No special phonological rules are needed since the underlying forms already satisfy the constraints.

A class of what we will call palatal-type consonants including semivowel /y/ and laminoalveolars /nyj/ is needed; see Palatal-Deletion P-26 (§3.27) which might be formally combined with yr-Contraction P-14 (§3.15). cf. also V-Fronting P-50 (§3.51).

Velar consonants /ngg/ can perhaps be considered a phonological class since they are maximally subject to point-of-articulation assimilation (sometimes leading to deletion) before another consonant. (Since labials do not normally occur as morpheme-final consonants, and since /m b/ do not occur as nonhomorganic first members of intramorphemic consonant clusters, it is indeterminate whether we should expand this "velar" class to include labials, as in other languages where "noncoronal," "grave," or "peripheral" consonants behave as a unit.)

A class of what we will call palatal-type consonants including semivowel /y/ and laminoalveolars /nyj/ is needed; see Palatal-Deletion P-26 (§3.27) which might be formally combined with yr-Contraction P-14 (§3.15). cf. also V-Fronting P-50 (§3.51).

Velar consonants /ngg/ can perhaps be considered a phonological class since they are maximally subject to point-of-articulation assimilation (sometimes leading to deletion) before another consonant. (Since labials do not normally occur as morpheme-final consonants, and since /m b/ do not occur as nonhomorganic first members of intramorphemic consonant clusters, it is indeterminate whether we should expand this "velar" class to include labials, as in other languages where "noncoronal," "grave," or "peripheral" consonants behave as a unit.)