This paper examines beliefs about language(s), showing how they are rooted in and help maintain a standard language ideology, i.e. the conviction that certain languages exist in uniform standardised forms and that such forms are desirable. Such an ideology is widespread, although not universal, and has influenced lay and expert approaches to the study of language(s), as shown, for example, in a discussion of the concepts “vernacular” and “variety”. Characteristics of the standard, like uniformity and determinacy, are postulated as ideal characteristics of all varieties. Speakers influenced by standard language ideology often interpret language contact and language “mixing” negatively as incompetent or sloppy language use. This paper discusses alternative ways of conceptualising language that might encourage a more positive view of multilingualism.