Primary word stress is typologically diverse. In some languages, the metrical structure of a word predicts the location of primary stress, while in other languages it does not. This diversity is considered through the lens of Harmonic Serialism (HS), a serial constraint-based theory, and it is argued that HS must incorporate a limited degree of parallelism to capture the typology. Namely, primary-stress assignment is simultaneous with foot-building and also mobile, being (re)assessed throughout a metrical derivation. But incorporating this parallelism into HS is both possible and desirable: the positive typological consequences of HS are preserved, and the implied formal divergence between the prosodic word and the foot with respect to parallelism echoes a fundamental distinction that is visible in a wide range of extant theoretical and empirical findings.

Bidirectional stress systems with internal lapses are rare and their existence has been recently called into question (Newlin-Łukowicz 2012). The present paper reports an acoustic study of secondary stress in Ukrainian based on polysyllabic words with lexical stress located at or near the right edge of the word. The results indicate that Ukrainian has an iteration of secondary stresses from the left edge towards the lexical stress, rather than in the opposite direction. This characteristic makes it metrically related to bidirectional stress systems with internal lapses (e.g. Polish), which invalidates the argument against such systems and proves the empirical adequacy of the metrical theories designed to account for these stress patterns.