Five studies explored the processing of ambiguous sentences like Martin maintained that the CEO lied when the investigation started/at the start of the investigation. The central question was why particular prosodic boundaries have the effects they do. A written questionnaire provided baseline preferences and suggested that clausal adjuncts (when the investigation started) receive more high attachments than nonclausal adjuncts (at the start of the investigation). Four auditory studies manipulated the prosodic boundary before the adjunct clause and the prosodic boundary between the matrix clause and its complement. They disconfirm every version of an account where only the local boundary before the adjunct is important, whether the account is based on the acoustic magnitude of the boundary or its phonological type (an intermediate boundary characterized by the presence of a phrase accent vs. an intonational phrase boundary characterized by both a phrase accent and a boundary tone). Instead the results support use of the global prosodic context, especially the relative size of the local boundary and the distant boundary.