This paper analyzes the discourse conditions governing the choice between extraposition and nonextraposition of that-clause and infinitival-VP subjects. On the basis of a large corpus of naturally occurring data, it is shown that nonextraposition requires that the content of the subject be discourseold or directly inferrable. If the content is discourse-new, then extraposition is necessary. The choice between extraposition and nonextraposition for discourse-old and inferrable subjects is examined and is shown to depend on the discourse status of the predicate and on whether it is the predicate or the subject that links to the following discourse. The paper ends with a discussion of the syntactic position of nonextraposed sentential subjects and concludes that it cannot be the same as that of fronted sentential complements. This means that the common discourse properties of fronting and nonextraposition must be linked to their common linear ordering properties, rather than to a common syntactic position.