substantive differences between Tagalog stress and Margi tone. Tagalog stress is realized as both length and high pitch, whereas Margi has underlying high and low tones but no tone-
related length contrast. Despite these differences in phonetic substance, however, there appears to be no functional difference between Tagalog stress and Margi tone other than the fact that
they link in different directions. In fact, the polarity effects in these two languages are strikingly similar.
Thus, the phenomenon of polarity is instantiated in the stress system of Tagalog. Since Pulleyblank 1986 has demonstrated that polarity is best viewed as an autosegmental process,
the facts of Tagalog stress lend further support to the claim that stress is an autosegment. In summary, I have proposed two slightly different analyses of Tagalog stress. Both of these
analyses depend crucially upon the assumption that stress behaves autosegmentally. The essential difference between them is that one analysis utilizes metrical feet while the other does
not. Under the non-metrical analysis, the autosegmental property of polarity is instantiated for stress in essentially the same manner as it is instantiated in Margi’s tonal system. Furthermore,
both analyses predict the attested typology of suffixes in terms of how an autosegmental accent might be expected to combine with segmental material.
5.4. Conclusion: Constraining the Interaction of Stress and Foot-Building
This chapter has utilized data from Mayo and Tagalog to support the Autosegmental Stress Hypothesis, which asserts that stress is an autosegment. This hypothesis makes it possible to
account for foot-related stress systems in terms of two independent processes: the construction of headless feet and the assignment of a stress autosegment to those feet. The inherent
headlessness of feet in Mayo was attested by the observation that, even though foot-building has to precede and follow reduplication, the assignment of stress to feet must necessarily be
delayed until the postlexical stage of the derivation. Indeed, the presence of heads during the lexical phonology, which would be required under the theories of HV and Hayes, would
greatly complicate the analysis.
Regarding the autosegmental nature of stress, two kinds of evidence were presented. First, lexical accent in both Mayo and Tagalog floats in the same manner as autosegmental tone is
known to float in a number of languages. Second, all instances of stress in Mayo’s unaccented words are accounted for via a single rule which inserts and links a stress autosegment from
right to left in the foot, if there is one, otherwise in the word. The latter situation provides another argument for the separation of stress and foot structure, insofar as many Mayo words
never undergo Mayo’s rule of foot-building even though they surface with stress. This supports the claim that stress may exist apart from foot structure at any point in the derivation, even in
surface representation.
As a direct consequence of the separation of stress and feet, it was noted that the Tagalog stress data may be explained either with or without the use of feet. In either case, the source of
contrastive stress in Tagalog is essentially the same as in Mayo, with one simple difference, whereas the Mayo stress contrast is due to the left-to-right linking of a floating lexical accent in
certain words, the Tagalog stress contrast is attributed to the right-to-left linking of the same
kind of accent in certain words. The advantage of the autosegmental theory of stress over other metrical theories is that the former provides a natural explanation for the apparent mobility of
lexical accent in Mayo and Tagalog, whereas this mobility cannot be explained in any principled manner if lexical accent is viewed merely as a static segmental feature.
Returning to the question of feet in Tagalog, it was demonstrated that a reasonable non- metrical analysis of stress is possible. In particular, all of the observed stress alternations may
be accounted for by treating stress in exactly the same manner as tone is treated in languages such as Margi, i.e., as an autosegment which links directionally to the edges of words. It was
argued, furthermore, that Tagalog’s NOMINAL -an clitic exhibits essentially the same type of polarity effect as that of Margi’s polarizing prefix section 2.2.2, and the corresponding
analyses are strikingly similar.
In summary, this chapter has provided evidence for the existence of headless metrical feet as well as foot-free stresses in Mayo. And it has likewise demonstrated that stress in Tagalog
behaves like autosegmental tone. The next chapter summarizes the autosegmental theory of stress and discusses some residual issues regarding the claim that stress is autosegmental.
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6. Toward a Unified Theory of Prosody
The preceding chapters laid out the theoretical motivation as well as a broad base of empirical support for the autosegmental theory of stress. The aims of this final chapter are
threefold. First, section 6.1 suggests how the proposed theory might be extended to account for two types of phenomena which were mentioned only briefly in chapter 2. These are
i. multiple degrees of stress, and ii. “long range” stress shift under clash, as in the English Rhythm Rule.
Next, section 6.2 discusses a potential objection to the autosegmental theory of stress. This concerns the observation that stress autosegments never seem to undergo the autosegmental
process of spreading. It is suggested, as a preliminary explanation, that stress cannot undergo spreading because to do so would conflict with its central function in setting off one element in
a representation as more prominent than all the others. The final aim of this chapter, which is covered in section 6.3, is to present a brief synopsis of the autosegmental theory of stress.
I begin with a discussion of how the theory proposed in chapter 2 might be extended to account for the existence of multiple degrees of stress within a single domain.
6.1. Accounting for Multiple Degrees of Stress
Although the focus of this study has been the development of a theory of stress placement, chapter 2 briefly mentioned two types of phenomena which imply the existence of some kind
of hierarchical relationship between individual stresses. One of these is the occurrence of multiple degrees of stress in a large number of languages. The other phenomenon might be
referred to as “long range” stress shift. Section 2.2.1 discussed the English Rhythm Rule as an example of this. In this section I suggest how the autosegmental theory of stress might be
extended in order to account for these two sets of phenomena.
Looking first at the occurrence of multiple degrees of stress, how might the autosegmental theory of stress be extended or augmented in order to account for this phenomenon? Before
attempting to answer this question, consider how the theories of Hayes, Hammond, and HV have handled multiple degrees of stress. Since each of these theories views the foot as a grouping
of abstract terminal elements, one of which has to be a head, it is quite natural for the heads of feet to themselves be grouped into super-feet, also known as cola Stowell 1979; Hammond
1987a or word trees Hayes 1981. One of the members of each colon or word tree is then designated as the head using the same kinds of devices that are available for designating one of a
foot’s terminal elements as the head of that foot. This process, which may be repeated for as many levels as necessary in order to derive all of the observed degrees of stress, was illustrated in
section 1.2.2.
The same basic approach may be applied to stressed feet that have been derived under my proposal. The only difference is that feet are headless in my theory, so it is not possible to
group heads into cola. Instead, the stresses themselves must be grouped into cola. A stress autosegment is then inserted and linked on a higher line in each colon. The docking point in
this case is a foot-level stress autosegment, and the direction of linking may or may not be the
