Before and after: sentence-internal and -external discourse relations

This study presents a corpora investigation (online available texts of written and spoken English) regarding the usage of the discourse connectives before and after in multi-sentence discourse. We focus on sentences that begin with a connective and analyse these along with the preceding text. Our results show that two discourse relations have to be derived for these sentences: a sentence-external and a sentence-internal one. The sentence-external relation holding between the temporal clause and a preceding sentence is responsible for the coherent placement of a before/after-sentence in a wider discourse context. In particular, before and after presuppose one particular discourse relation, viz. ELABORATION. In addition, a sentence-internal discourse relation holds between the temporal clause and the main clause.