Raymond Harris-Northall uses the distinctive features of generative phonology to present synchronic and diachronic rules, but exploits the evidence of the history of the Spanish sound system to show that the 'simplicity' required by the generativists often obscures rather than illuminates the way in which changes develop from small beginnings. Instead, he illustrates the essential need to recognise the relevance of syllable structure constraints, which, allied with a complex but justified and helpful presentation of the relevant strength hierarchies, allow him not only to describe but to...