11.2.1 Harmony
Finite-state models of phonology have also been applied to more sophisticated phonological and morphological phenomena. Let's consider a finite-state model of a well-


known complex interaction of three phonological rules in the Yawelmani dialect of Yokuts, a Native American language spoken in California. $ ^{4} $
First, Yokuts (like many other languages including for example Turkish and Hungarian) has vowel harmony. Vowel harmony is a process in which a vowel changes its form to look like a neighboring vowel. In Yokuts, a suffix vowel changes its form to agree in backness and roundness with the preceding stem vowel. That is, a front vowel like /i/ will appear as a back vowel [u] if the stem vowel is /u/. This Harmony rule applies if the suffix and stem vowels are of the same height (e.g., /u/ and /i/ both high, /o/ and /a/ both low): $ ^{5} $

| | High Stem | Low Stem | | | | |
| --- | --- | --- | --- | --- | --- | --- |
| | Lexical | Surface | Gloss | Lexical | Surface | Gloss |
| Harmony | dub+hin\nxi+lin | $ \rightarrow $ dubhun\nxiil+xin | “tangles” “leads by the hand” | bok'+al\nxat'+al | $ \rightarrow $ bok'ol\nxat'al | “might eat” “might find” |
The second relevant rule, Lowering, causes long high vowels to become low; /u:/ becomes [o:] and /i:/ becomes [e:], while the third rule, Shortening, shortens long vowels in closed syllables:
| Lowering | Shortening | ||||
| ?u:t'+it | → | ?ot'ut | “steal, passive aorist” | s:ap+hin | → saphin |
| mi:k'+it | → | mek'+it | “swallow, passive aorist” | sudu:k+hin | → sudokhun |
The three Yokuts rules must be ordered, just as the ix-insertion and z-devoicing rules had to be ordered. Harmony must be ordered before Lowering because the /u:/ in the lexical form /?u:t'+it/ causes the /i/ to become [u] before it lowers in the surface form [?ot:t'ut]. Lowering must be ordered before Shortening because the /u:/ in /suduk+hin/ lowers to [o]; if it was ordered after shortening it would appear on the surface as [u].
The Yokuts data can be modeled either as a cascade of three rules in series, or in the two-level formalism as three rules in parallel; Fig. 11.6 shows the two architectures (Goldsmith, 1993; Lakoff, 1993; Karttunen, 1998). Just as in the two-level examples presented earlier, the rules work by referring sometimes to the lexical context, sometimes to the surface context; writing the rules is left as Exercise 11.4 for the reader.