Diachronic opacity from protracted change in Proto-Germanic

Abstract

It is well known that sound changes differ in their duration. Some changes remain active across multiple periods of development; other changes are relegated to a narrow, discrete time frame. Many relative chronologies in historical phonology do not take these durational differences into account. In this chapter, I examine one such instance. I argue that early i-umlaut in Proto-Germanic was a protracted change. Because this development was active concurrently with other later-occurring sound shifts, some forms in relative chronology are opaque, similar to synchronic examples of counterbleeding or overapplication. Understanding this opacity — and being mindful of it — is crucial for evaluating relative chronology and improving reconstruction efforts.