Vowel assimilation across syllable boundary

Sequences of /i/ across morpheme boundary produced in rapid speech usually participate in syllable amalgamation. When the two /i/ phonemes, as a result of syllable amalgamation across word boundary, appear in the same syllable, a long vowel, [i:] is produced, phonetically identical to the [i:] realization of the vowel phoneme, /ii/. This supports our proposal to treat long vowels as being phonologically a sequence of two identical vowels. Examples are presented in (10) below.

We have posited that the most complex syllable nucleus involves a VV sequence, i.e. either a long vowel or a diphthong. This is demonstrated by syllable amalgamation across morpheme boundaries involving V and VV sequences as in the example below. There, we see an underlying sequence of V+VV, i.e. /u + aa/, becoming C+VV, /w + aa/, with the C being the semi-vowel, /w/, carrying the feature [back] previously associated with the underlying /u/ vowel. A VVV syllable is avoided by the device or converting the vowel /u/ to the corresponding semi-vowel, /w/, i.e. making it function as a feature superimposed on a preceding consonant rather than a vowel.

The rule which triggers syllable amalgamation across a amorpheme boundary also applies to sequences of /u + i/. This demonstrates another aspect of our basic vowel analysis. We already noted that the sequence */ui/ is not possible within the same syllable nucleus. In the example below, when /u + i/ merge to produce a single syllable, adjustments there need to be made. In order to eliminate the tautosyllabic */ui/ sequence, the [back] feature borne by /u/ is shifted into a consonantal position in the onset, producing the semi-vowel /w/. This shift of the [back] feature to a consonant slot leaves the complex syllable nucleus with an unfilled vowel slot. This is filled by a spread of the values of the [back] and [high] features from the remaining vowel in the nucleus, producing a tautosyllabic [w + i:] sequence as in the examples below.

This establishes what we have already proposed, that vowels with the features [high] and [back] cannot co-occur in the same syllable nucleus. Thus, the amalgamated syllable has been modified to accommodate the principle that high vowels occurring in the same syllable have to agree for the feature [back]. In our discussion of JamC syllable structure, we shall see that vocalic sequences [ui] and [iu] only occur provided the initial vowel in the sequence occupies a C-slot, i.e. functions as a semi-vowel.

Some syllables with the double vowel, /ii/, are the product of lexical specification with the vowel /ii/, e.g. an item like /tiit/ ‘teeth’, while others are derived from syllable amalgamation across word boundary, e.g. /siit/ < /si it/ ‘see it’ and /dwiit/ from /du it/ ‘do’. Irrespective of their derivation, however, these double vowel sequences are treated within the phonological system of JamC as identical. This is demonstrated by the rhyme below. The nucleus /ii/ produced by lexical specification in /tiit/ participates in a rhyme with two syllables, /siit/ and /dwiit/, whose vowel /ii/ is the product of syllable amalgamation.