‘Multilingualism’ asks: Why should bilingualism (or multilingualism) be of particular sociolinguistic interest? Speaking a particular language means belonging to a particular speech community; speaking two or more may imply some sort of dual citizenship. Since language is a central personality trait, one possibility is that bilinguals have an identity woven out of more than one linguistic thread. Another is that personalities themselves may be dual. Much of interest rests upon the degree to which bilinguals possess either two (theoretically) separate systems of language, from each of which they can draw as circumstances warrant, or some more intertwined linguistic capacity.