Criteria for differentiating inherent and contact-induced changes in language reconstruction

The paper discusses two progressive accent shifts which happened in Slavic during the post-migrational period before the end of the first millennium AD. Both shifts cross-cut the preceding pattern in Slavic, yet the first of these was relatively general and the second was highly restricted. In addition, the first of these shifts, referred to as Dybo’s law, occurred as part of a sequence of changes, whereas the second was an isolated phenomenon. The paper shows that both shifts can be explained in terms of emerging weight properties within trochaic feet, yet against the background of a different ranking of tone and quantity. Keywords: Dybo’s law; Stang’s law; Slovene progressive shift; resolved trochee; prosodic hierarchy