Consonant Cluster Alternations in Pawnee : An Optimality Account ∗

I examine in this study certain consonant cluster alternations in Pawnee, and propose an Optimality-theoretic account. The alternations discussed in this work involve a number of distinct phonological processes. I argue that, while they are diverse in quality, these alternations are triggered for the same reason: to optimize syllable contact (Venneman (1988)). This analysis has the following advantages: (i) unlike a rule-based analysis as in Parks (1976), this constraintbased analysis gives an unified account for the alternations that would otherwise seem unrelated to one another; (ii) in addition, it follows from this analysis why geminates are not allowed in Pawnee; (iii) it explains why different geminates undergo different degemination processes.


Introduction
I examine in this study certain consonant cluster alternations in Pawnee, and propose an Optimality-theoretic account.The alternations discussed in this work involve a number of distinct phonological processes.I argue that, while they are diverse in quality, these alternations are triggered for the same reason: to optimize syllable contact (Venneman (1988)).This analysis has the following advantages: (i) unlike a rule-based analysis as in Parks (1976), this constraintbased analysis gives an unified account for the alternations that would otherwise seem unrelated to one another; (ii) in addition, it follows from this analysis why geminates are not allowed in Pawnee; (iii) it explains why different geminates undergo different degemination processes.

Background
Pawnee belongs to the northern branch of the Caddoan language family along with Wichita and Arikara (Parks (1976)).The people of Pawnee currently live in and around the town of Pawnee, Oklahoma.However, there is no fluent speaker today (Parks (p.c., May 2005)).First of all, Pawnee lacks in voiced obstruents.Second, Pawnee has a relatively robust series of alveolar consonants, but it only has a very limited number of phonemes for the labial, velar, and laryngeal.As it will become clear, this second point crucially bears on our main discussion of geminates in Section 5.

Observations
As the contrast between (1) and (2) illustrates, the voiceless alveolar stop /t/ undergoes alternations when it is followed by a homorganic consonant.
While the above contrast indicates that homorganic consonants play a crucial role in triggering the alternations, it is important to observe that the output clusters remain homorganic.This observation thus suggests that, while homorganicity is relevant, there is another essential factor inducing the alternations.
I argue that these alternations are triggered to improve the transition between syllable boundaries.More specifically, clusters undergo alternations in such a way that the coda becomes more sonorous than the following onset.In summary, I claim that the alternations are induced when homorganic consonants come in contact, and if the first segment is not more sonorous than the second.

Constraints
In order to account for the above syllable transition fact, I adopt a version of the syllable contact condition (Venneman (1988)) defined in terms of sonority (e.g., Davis and Shin (1999)) as shown in (3a). 3In addition, I adopt an OCP constraint (Goldsmith (1976)) to account for the homorganicity effect.Since the alternations are present only when both of the two constraints are simultaneously violated, I propose to conjoin the two constraints as in (3c).
(3) Main constraints a. SYLLCON: the coda of a syllable must be higher in sonority than the onset of the immediately following syllable (i.e., "avoid rising and flat sonority over a syllable boundary).4 b. OCP[place]: avoid consecutive segments with the identical place specification (i.e., "avoid homorganic clusters").c.LC: local conjoined constraint of SYLLCON and OCP[place], where the domain is adjacent syllables.
To evaluate SYLLCON, we adopt the following sonority scale.
(4) Adopted sonority scale Stops Affricates Fricatives Liquid (least sonorous) (most sonorous) We assume that fricatives are more sonorous than stops.In addition, we assume with Hankamer and Aissen (1974) that the sonority of affricates falls somewhere between that of stops and that of fricatives.Note here that it is possible to "repair" bad consonant clusters either by avoiding bad sonority sequence or by avoiding consecutive homorganic segments.In particular, (a) manner alternations, (b) metathesis, or (c) cluster reduction may be in principle induced to avoid bad sonority sequence; (d) change of place or cluster reduction may be induced to avoid homorganicity.Based on this observation, I propose the faithful constraints in ( 5), which are antagonistic to the markedness constraints in (3).
(5) Additional constraints a. IDENT[manner]: corresponding segments in the input and output must be identical with respect to the manner specification (i.e., "avoid manner alternations").b.LINEARITY: corresponding segments in the input and output must be in the same order (i.e., "no metathesis") c.MAX: the segments in the input must have corresponding elements in the output (i.e., "no deletion").d.IDENT[place]: corresponding segments in the input and output must be identical with respect to the place specification (i.e., "no change of place").

Constraint ranking
Let us now consider the ranking of the constraints.First, LC must be ranked higher than its conjuncts as shown in ( 6) to have its "intended" effect.
(6) Partial ranking 1: LC >> SYLLCON, OCP[place] The above partial ranking is universal to any conjoined constraint since the violation of an individual conjunct is tolerated as long as the whole is not violated.Second, to avoid a violation of LC, Pawnee opts for manner alternations, rather than cluster reduction.The presence of manner alternations itself suggests that IDENT[manner] is outranked by LC, and since Pawnee prefers manner alternations to cluster reduction as illustrated in ( 7

Absence of Alternations
As we discussed earlier, no alternation is triggered when non-homorganic consonants come in contact with each other as illustrated in ( 12). ( 12

Affrication and stopping
We saw in (1) that both manner alternations and metathesis are observed in Pawnee.However, as illustrated in ( 16), Pawnee resorts to a manner alternation, rather than metathesis, when both are in principle available.
( .The OT analysis presented here thus suggests that the apparent metathesis be analyzed as a case of manner alternations, in particular a combination of affrication and stopping as shown in (23d).

Support: Geminates
The OT analysis presented here makes predictions about geminates in Pawnee.Observe that some geminates undergo manner alternations (24a/b) while others undergo cluster reduction (24c/d).This asymmetry follows from the OT analysis.
Recall that, when LC is violated, manner alternations are usually evoked in Pawnee, rather than cluster reduction or metathesis (see ( 7) and ( 16), respectively).In addition, when manner alternations are triggered, the clusters always alternate with homorganic consonants, suggesting undominated IDENT [place].Given the fact that /k/ is the only velar phoneme in Pawnee, manner alternation of /k/ necessarily incurs a violation of undominated IDENT [place].On the other hand, alveolar consonants alternations without violating IDENT [place].The contrast in (24) therefore suggests that a violation of MAX is tolerated in order to satisfy IDENT[place] (i.e., IDENT[place] >> MAX).Second, since MAX crucially outranks IDENT[manner] as we saw in (7), Pawnee opts for manner alternations, rather than cluster reduction.Note here that, while the alternation of /ss/ is consistent with this pattern, the alternation of /kk/ is not.In summary, the asymmetry between manner alternations and cluster reduction follows from an asymmetry in the phonemic inventory once the present OT analysis is adopted.

Residual issue
As we just saw, geminates undergo manner alternations when they have homorganic consonants to alternate with; they undergo cluster reduction instead when they do not have homorganic consonants.However, as the tableau in (28) shows, the geminate /rr/ presents itself as an apparent counter example to these patterns.
( This additional undominated constraint keeps the outcome of any of the cases we discussed earlier intact.For example, the tableau in (30) shows that the additional undominated constraint does not affect the outcome of the metathesis case.Since none of the candidates, including the optimal output, does not violate IDENT[sonorant], the same candidate is chosen as the optimal output both in ( 23) and (30).

Conclusions
In this paper, I demonstrated that the syllable contact condition (defined in terms of sonority) was partially responsible for the various consonant cluster alternations in Pawnee.I then proposed an Optimality theoretic account.Crucially, observing that the syllable contact condition is in effect only in homorganic clusters, I proposed to conjoin the syllable contact constraint (SYLLCON) with the "anti-homorganic cluster" constraint (OCP[place]).Since all the geminates necessarily violate this conjoined constraint, the proposed analysis correctly predicts Pawnee's aversion to geminates.
In addition, observing that all the manner alternations preserve their manner specification, I claimed that IDENT[place] is undominated in Pawnee.While they usually undergo manner alternations, geminates undergo cluster reduction instead in cases where IDENT[place] would be otherwise violated (e.g., /kk/[k]).Geminate also exhibit cluster reduction if IDENT[sonorant] would be otherwise violated (e.g., /rr/[r]).These two cases of cluster reduction are motivated

Table 1 ,
Pawnee has a relatively small number of consonants.

Table 1 :
Phonemic Inventory of Pawnee Consonants ), MAX is ranked higher than IDENT[manner].In addition, it is important to note that the Pawnee manner alternations always preserve place specification.This fact indicates that IDENT[place] is undominated in Pawnee.The following is thus our preliminary ranking of the constraints.
) No alternations with non-homorganic clusters only violates one of the conjuncts.Finally, while (15b) violates a high-ranked faithfulness constraint (IDENT[manner]), (15a) does not since it is a faithful candidate.Therefore, the faithful candidate is chosen optimal.
With this revised ranking of the constraints, consider the tableau for the metathesis case.
First of all, since geminates are by definition homorganic, they necessarily violate OCP[place].In addition, since they always have "flat" sonority, they necessarily violate SYLLCON as well.Therefore, geminates necessarily violate the undominated LC constraint.It is thus predicated that geminates are not allowed in Pawnee.As illustrated in (24), this prediction is borne out.
While both violate low-ranked IDENT[manner], only the (b) candidate in (27) fatally violates the undominated IDENT[place].As a result, the (b) candidatewith manner alternation is selected as the optimal candidate for the /ss/ geminate on the one hand; the (c) candidate with cluster reduction is chosen for the /kk/ geminate on the other. 8 Pawnee there is an undominated constraint that militates against alternations from a sonorant to an obstruent, or vice versa.Consider the following tableau with this new constraint, IDENT[sonorant].