This article has two main parts. In the first, the subject pronoun in a cleft sentence together with the cleft clause is shown to function pragmatically as a discontinuous definite description. Applying the GIVENNESS HIERARCHY (Gundel et al. 1993) makes it possible to explain the distribution of this-clefts and that-clefts in discourse, and predicts the more frequent occurrence of it-clefts. Clefts also semantically share existential and exhaustiveness conditions with definite descriptions. The second part presents a new syntactic analysis of clefts, which treats the cleft clause as an extraposed complement of the cleft subject pronoun, adjoined to the clefted constituent.