4 Quantity

Quantity plays an important role in the analysis of a wide variety of phonological and morphological phenomena in many languages including the analysis of word stress, tone, compensatory lengthening, shortening processes, minimal word requirements, templatic restrictions and allomorphy selection. These phenomena frequently distinguish between syllables that are short (or light) from those that are long (or heavy). In the fi rst section of this chapter we introduce the theory of moraic phonology of Hayes (1989a), a representational theory of quantity. In subsequent sections we overview a number of issues that emerge from moraic theory. In our discussion of these issues we will refer to the wide variety of processes in which quantity plays a role. In modern studies of phonology, the term “quantity” refers to either segmental duration or syllable weight. With respect to segmental duration, quantity differences among segments are said to be phonemic in languages that contrast a long and short form of a vowel of the same quality and in languages that contrast a geminate versus non-geminate consonant. The Japanese examples in (1) illustrate both types of contrasts.