This article argues that, contrary to some recent proposals, a given phonological form may be organised into at most one array of metrical structure at a time. The bulk of the paper is dedicated to a case study of Huariapano, a language that has been claimed to motivate multiple, coexisting but autonomous, layers of metrical parsing. I show that this conclusion is premature: both stress and segmental patterning in Huariapano can be modelled within a single system of constituency, once context-dependent variation in foot form is taken into account. The reanalysis developed here also draws on the idea that foot-initial syllables may be targeted by augmentation or fortition processes even when unstressed. Independent evidence for foot-initial strengthening is furnished by segmental phonotactics in a range of other languages.

This paper examines two related phenomena from Catalan that pose a challenge to a proposal in McCarthy (2012) that combines Harmonic Serialism (HS) with the theory of Optimal Interleaving (OI) of Wolf (2009). The first phenomenon, found with stems ending in a sibilant, is the selection of a marked masculine allomorph only before the plural morph, also a sibilant, which prevents an OCP violation. The second, phrasal, phenomenon is restricted to one dialect of Catalan: the plural morpheme is not realised in prenominal position only when it would surface between two consonants. It is shown that, with some crucial modifications on the way spell-out proceeds, HS/OI can account for the two phenomena when they occur separately, but when they co-occur within the same phrase, wrong predictions are made, due to the one-change-at-a-time basic property of HS. These problems do not arise in a parallel OT approach.

Obstruents in Russian have been claimed to assimilate in voicing in clusters when a sonorant consonant intervenes, e.g. ot mgly [dmg] ‘from the haze’. This phenomenon (‘sonorant transparency to voice assimilation’) is controversial: it is claimed to be a phonological rule of fast speech by some linguists, while its existence is denied by others. Previous studies have shown that voicing in presonorant obstruents (C1) in Russian is consistent with that of prevocalic obstruents in slow speech; however, no research has examined whether voicing in presonorant obstruents changes either as a function of the voicing of the rightmost (C2) obstruent in a cluster or in faster speech. This paper presents experimental results supporting the claim that the voicing of C2 obstruents does not affect voicing in presonorant C1 obstruents in slow or fast speech. The results suggest that obstruents do not assimilate through a sonorant in obstruent–sonorant–obstruent clusters in Russian.

Phonological rules can be variable in two ways: they can apply to a subset of the lexicon (lexical variation), or apply optionally, with a probability that depends on the phonological environment (stochastic variation). These two types of variation are occasionally seen as mutually exclusive. We show that the vowel–zero alternation in Russian prepositions ([s trudom] ‘with difficulty’ vs. [sə stinoj] ‘with the wall’) exhibits both types of variation. In two corpus studies and a nonce-word experiment, we document novel stochastic factors that influence the alternation: similarity avoidance, stress position and sonority profile. These constraints interact additively, lending support to a weighted-constraints analysis. In addition to phonologically determined stochastic variation, we find significant lexical variation: phonologically similar nouns differ in the rate at which they condition the alternation in the prepositions. We analyse this pattern by augmenting the weighted-constraints approach with lexical scaling factors.