Irish English is both the oldest overseas variety of English and, thanks to its co-existence with Irish Gaelic, one of the longest-documented examples of a contact-influenced language variety. The dual aspects of substratal influence and dialectal conservatism, together with the spread of this variety in the Irish diaspora and its use in literature, provide the main impetus for research into Irish English. This volume brings together 12 original papers which use a variety of methods to examine these aspects of English in Ireland. Following a historical introduction which looks critically at received views of language diffusion in Ireland, three papers directly address the role of the Irish-language substrate in Irish English. Detailed studies also describe non-standard syntax in Belfast, systems of dental and alveolar phonemic contrast, contemporary sound change in Galway, Irish English prosody, dialect wordlists, and the uses of Irish English, notably Ulster Scots, in contemporary literature. The North American perspective investigates the role of Irish English in Newfoundland, and examines a corpus of 18th-century documents which reflects the language brought to the United States in the early development of American English. The range of approaches and data included make this book relevant to all those interested in language contact, diffusion, change, and variation.