The study of lesser-known varieties of English is opening up new research. Over the last twenty years or so, the role(s) and function(s) of English around the world have received a great deal of interest from linguists concerned with research on topics as diverse as sociolinguistics, variation and change, contact linguistics, language typology, genetic linguistics, etc. Kachru's work (The Inner Circle, the Outer Circle, and the Expanding Circle) inspired others and alternative models were put forward by McArthur (1987) and Görlach (1990). Though they differ on how the varieties should be classified (varying in criteria such as geographic distribution, usage and function, development history, etc.), they share the idea that varieties of English can be grouped in first- (or native-), second- and foreign-speaker groups.