This book explores how ethnic division interacts with variation and change in Northern Irish English. It identifies an idealised folk model of harmonious communities, in spite of the social divide and open conflict that have long affected the region; this model affects daily life and sociolinguistic studies alike. A reading of sociolinguistic studies from the region reveals ethnolinguistic differentiation. Qualitative analysis of material from (London)Derry shows people often stressing tolerance in their community, while accounts of their activities contain evidence of ethnic division and strife. Quantitative analysis charts six changes in (London)Derry English. Variation correlates to varying degrees with age, ethnicity, class, sex and social network. The ethnic dimension, while not the most important parameter in all cases, plays a role in relation to all the changes examined.