Grammaticalising the perfect and explanations of language change : have and be perfects in the history and structure of English and Bulgarian In Grammaticalising the Perfect and Explanations of Language Change: Have and Be Perfects in the History and Structure of English and Bulgarian Bozhil Hristov investigates key aspects of the verbal systems of two distantly related Indo European languages highlighting similarities as well as crucial differences between them and seeking a unified approach. The book reassesses some long held notions and functionalist assumptions and shines the spotlight on certain areas that have received less attention such as the role of ambiguity in actual usage. The detailed analysis of rich contextualised material from a selection of texts dovetails with large scale corpus studies complementing their findings and enhancing our understanding of the phenomena. This monograph thus presents a happy marriage of traditional philological techniques and recent advances in theoretical linguistics and corpus work Introduction Theoretical preliminaries The story of the English perfect The development of the perfect in a selection of Old English texts Further development of the perfect based on a selection of texts from Middle to Modern English How things could have been: a glance at German The perfect in the history and structure of Bulgarian The development of the perfect in a selection of Middle and Modern Bulgarian texts Conclusions.