A commonly held view of English definite articles is that the referent of an NP is familiar to the addressee. However, it is well known that not all definite article phrases meet this familiarity requirement. To account for such nonfamiliar uses, Heim (1982) invokes the mechanism of 'accommodation', which enables an addressee to remedy a violation of the familiarity requirement by adding assumptions to the 'common ground'. In this article we argue that the Givenness Hierarchy framework provides an insightful account of all uses of definite article phrases without requiring an appeal to accommodation. Such an account provides a unified treatment of definite article phrases, including demonstrative phrases and personal pronouns, while at the same time distinguishing among them in a principled way. This proposal is supported by results of a corpus-based examination of the use of definite articles and by an examination of cleft presuppositions.