So far in this course, we have only been concerned with the semantic interpretation of single sentences. When we look at discourse , i.e. sequences of sentences, interesting challenges arise that go beyond the tools and techniques for computational semantics we have developed up till now. One of these challenges is interpreting pronouns - words like ``he'', ``she'' and ``it'' which indirectly refer to objects. In this chapter we will introduce Discourse Representation Theory (or DRT for short) and show how one can build semantic representations of texts and develop algorithms for resolving pronouns to their textual antecedents.