In a world where an increasing amount of communication takes place online, this study presents data from email exchanges to provide the first examination of sociolinguistic competence and the acquisition of native-like variability in an English as a Lingua Franca (ELF) context. The data provided by online interactions between Swiss speakers (with German, French and Italian mother tongues) and the analysis of the specific variables of futurity, relatives, complementizers and adverbials allow the reader to gain a greater understanding of which features of discourse are source language related and which are learning related. This book will be of interest to postgraduates and researchers interested in language variation and change, ELF and second language acquisition, as well as to undergraduates wanting guidance on different ways of examining sociolinguistic variables.