The current thesis presents a detailed study of the earliest evidence of Old English to investigate the early Old English sound change known as breaking. The aims of the study are twofold: firstly, it investigates the early development of the Old English orthographic tradition and the external influences which might have affected it and, secondly, it interprets the orthographic evidence to explore the phonological characteristics of this sound change. The corpus used to achieve these aims includes the Old English material from Latin charters, five glossaries of the Leiden family, six manuscripts of Bede’s Historia Ecclesiastica Gentis Anglorum, two copies of Cædmon’s Hymn, a copy of Bede’s Death Song, a copy of the Leiden Riddle and Anglo-Saxon coin epigraphy. An understanding of the early development of the orthographic system of Old English enriches our understanding of this language, its scribes, the scribal centres in which it was used and the intellectual climate of Anglo-Saxon England in the early Middle Ages. This thesis argues that a change took place in the orthographic representations of the vowels affected by breaking throughout Anglo-Saxon England in the eighth century. This change may have been part of a wider development towards an independent Old English spelling tradition, while the earlier Old English textual materials show a stronger influence from external spelling traditions. The orthographic evidence provides no support for interpretations of breaking as an allophonic change, as argued by Daunt (1939, 1952) and Stockwell and Barritt (1951, 1955, 1961). It might be consistent with a monophthongal interpretation of the vowels affected by this process, as argued by Hockett (1959), but this thesis concludes that the traditional view of breaking as diphthongisation is the more convincing interpretation of the extant evidence.

Dialect emergence or new-dialect formation in intensive contact situations has been the subject of research for decades. Approaches to dialect emergence have led to a more solid understanding of the origins of specific phonological features. This line of research often approaches issues of new-dialect formation and phonological feature development within the confines of one linguistic subfield. However, new-dialect formation is a multifaceted phenomenon which results from a combination of dialectological, phonological and historical linguistic factors. The current thesis presents a comprehensive account of phonological feature development in new-dialect formation from a combined theoretical perspective by exploring historical and contemporary processes in the emergence of phonologically-conditioned variation in the price and mouth lexical sets in Liverpool English. This feature has been widely researched in other varieties of English and has previously been attributed to new-dialect formation. However, little is known about the patterns of price and mouth in Liverpool English. The current thesis relies on multiple methods of data collection (e.g. a combination of fieldwork and corpus data), various quantitative methods, and detailed acoustic analyses (e.g. formants and Euclidean distance in a two-dimensional formant space) to investigate the precise details and the processes involved in the emergence and development of price and mouth patterns in Liverpool English. Liverpool English is thought to have emerged during the 19th century as a result of extensive and prolonged immigration from the surrounding areas of Lancashire and Cheshire, and from Ireland, Wales, and Scotland. However, the specific timing, extent of immigration, and proportion of immigrant populations have not been investigated in detail. The current thesis provides the first in-depth analysis of historical census records in order to extend our knowledge of the populations in Liverpool at the time of new-dialect formation. The insights obtained from this analysis provide a more nuanced picture of the development of Liverpool English. They are essential for determining what dialects potentially contributed to dialect formation and the repertoire of price and mouth variants present at the time that these processes were developing. The analysis of historical census records is further augmented by using a combination of quantitative methods and historical corpora in order to gain a fuller understanding of the processes involved in the formation of these dialect features. The contemporary investigation of price and mouth in Liverpool English shows that these patterns are separate, but related, and that their phonological conditioning environments resemble those reported for cases of price and mouth variation in other varieties of English. I present a detailed overview of the phonetics and phonology of price and mouth variation in Liverpool English, looking at a wide range of conditioning environments. This investigation also reviews a range of different quantitative measurements useful for research on variation involving diphthongs. The origins of price and mouth phonological patterns in Liverpool English indicate that an approach combining different theoretical perspectives is required to adequately explain the development of these patterns. The current thesis suggests that price and mouth phonologically conditioned variation in Liverpool English initially resulted from variants of different dialects within the dialect contact situation. However, some features of the contemporary patterns developed following new-dialect formation as a by-product of phonetic and phonological properties of diphthong production in certain following environments. By approaching the development of these phonological features in Liverpool English from a combination of theoretical perspectives, the current thesis expands our understanding of emergent phonological features in new-dialect formation.