Restrictions on the position of exh

The grammatical approach to scalar implicatures attributes their introduction to a covert operator exh, which can be posited in various structural positions. By studying the interaction of scalar implicature calculation and the presuppositions of English also and again, we are able to pinpoint the structural position of exh. This diagnostic shows that some triggers of scalar implicature require exh to be adjoined as low as possible above them, whereas other triggers allow for more delayed adjunction of exh. We offer a concrete proposal for these behaviors in terms of syntactic feature-checking and show how it extends to cases involving ignorance inferences.