Coherence Relations, Ellipsis and Contrastive Topics

A highly pervasive phenomenon in natural languages is ellipsis. It is commonly believed that the presence of ellipsis is one of the main reasons why natural language is as ambiguous as it is. If lexical material is left unpronounced, a hearer must rely on other parts of the sentence, on contextual information and on intonation to recover the unpronounced material. Because there may be different options within the sentence for recovery of unpronounced material, elliptical sentences can be ambiguous. Also, the context in which the sentence appears can differ, which may lead to different readings. Finally, the sentence may be compatible with different patterns of intonation. Because intonation can have truth-conditional effects, this may also increase the number of readings of a sentence. In a number of cases, however, ellipsis decreases rather than increases the number of readings of a sentence. Consider the following sentences from Levin and Prince (1986):