Some phonologically significant generalizations result from processes, often formalized as rewrite rules, while others result from interactions among independently motivated processes, often formalized in terms of serial ordering. We adopt these general formalizations of processes and interactions to address two questions. One is the interaction question: what are all the possible forms of interaction between two processes? The other is the opacity question: what makes an interaction between two processes opaque? We show that these questions are best addressed with a rigorous algebraic formalization of processes and their pairwise interactions, describing the complete formal typology of process interactions and identifying the formal properties of those interactions that lead to different types of opacity.

We present an empirical challenge to Jardine's (2016) assertion that only tonal spreading patterns can be unbounded circumambient, meaning that the determination of a phonological value may depend on information that is an unbounded distance away on both sides. We focus on a demonstration that the ATR harmony pattern found in Tutrugbu is unbounded circumambient, and we also cite several other segmental spreading processes with the same general character. We discuss implications for the complexity of phonology and for the relationship between the explanation of typology and the evaluation of phonological theories.

This paper is about opaque interactions between phonological processes in the two senses defined by Kiparsky (1971, 1973) and discussed in much recent work on the topic, most notably McCarthy (1999) : underapplication opacity, whereby a process appears to have failed to apply in expected contexts on the surface, and overapplication opacity, whereby a process appears to have applied in unexpected contexts on the surface. Specifically, I demonstrate that there are three distinct types of overapplication opacity in addition to the only case discussed and properly categorised as such in the literature, counterbleeding. The analysis of each type of opacity in terms of rule-based serialism and in terms of Optimality Theory is discussed, emphasising the strengths and weaknesses of the two frameworks in each case.

Avoidance of adjacent consonants that are ‘sufficiently identical’ – that is, identical except for possible differences in a small subset of specific features – is argued to result from joint satisfaction of a constraint against geminates (identical adjacent consonants) and other active constraints that independently require assimilation with respect to those features ignored in the determination of identity. The crux of the proposal is the dependence of antigemination on independent assimilation processes, a prediction that is independently verified in case studies from English and Lithuanian. The factorial typology of constraints at the core of the proposal is demonstrated to closely fit a significant range of observed cases.

This volume consists of a subset of the papers presented at a workshop on Prosodic Morphology which took place in June 1994 at the Research Institute for Language and Speech at Utrecht University.We wish to acknowledge the helpful comments of Colin Wilson and Rachel Walker, neither of whom should accept any responsibility for any remaining errors or unreadability. There are two main themes that hold the volume together; the first and most obvious theme is the interface between morphology and phonology/prosody, and the second is the use of Optimality Theory (OT; Prince & Smolensky 1993) to analyse aspects of this interface. We comment on the individual chapters of the volume in § 2 below, and offer some general concluding remarks in § 3.