How English Has Become a Vowel-Shifting Language

English has long been suspected to be a vowel-shifting language. This hypothesis, often only adumbrated in previous work, is closely investigated in this book. Framed within a novel framework combining evolutionary linguistics and Optimality Theory, the account proposed here argues that the replacement of duration by quality as the primary cue to signaling vowel oppositions has resulted in the ‘shiftiness’ of many post-medieval English varieties.