Explaining branchingness effects in phrasal phonology

A wide variety of languages have been shown to have phonological rules whose domains of appli-cation are larger than words but smaller than intonational phrases or utterances. Within the theory of prosodic phonology, such rules correspond to the level of the Phonological Phrase, and for convenience I will use the cover term phrasal rules for them. However, the goal of this paper is to show that these rules do not comprise a single uniform class, but rather have two distinct sets of properties, which are argued to correspond to two separate stages of domain specification. This treatment offers some explanation for why different phrasal rules have different properties, and brings to light several correlations of potential interest that are otherwise obscured. 1 Background: phrasal rules and prosodic hierarchy theory One of the characteristic properties of phrasal rules is that their domains appear to be constrained by the syntax to a certain extent. As such, these rules provide a potential source of information about the nature of PF and the derivation from syntax to phonology. However, the general assumption in the literature is that phonological rules refer only indirectly to syntactic structure—i.e., phonological rules cannot ‘see ’ the syntax directly but instead refer to a level of derived intermediate structure. Some frequently cited motivations for the indirect reference approach include (a) the fact that phonological domains do not always correspond to syntactic constituents, and (b) the fact that phonological rules do not operate on the full range of information available in a syntactic phrase marker.2 Within the theory of prosodic phonology (Nespor and Vogel, 1986, inter alia), the derived structure that phonological rules apply to is instantiated as a strictly layered hierarchy of prosodic constituents, with phrasal rules corresponding to the Phonological Phrase (φ) level: (1) Prosodic hierarchy (subword constituents not shown):