Title: The role of alternatives and strength in grammar
Description: The present thesis investigates the role of semantic alternatives and logical strength in a number of empirical domains. Firstly, the thesis deals with the semantic contribution of focus on (bound) pronouns (chapters 2-3). The main results are as follows: First, focus on bound pronouns is interpreted by an operator (Rooth 1992b) in the scope of the binding quantifier. Second, contrastiveness is encoded in the semantics of the operator interpreting focus. Third, it is argued that the grammar must allow for the concept of compositional reconstruction , which makes it possible to generate more alternatives for focus licensing than would otherwise be available. Lastly, it is suggested that Schwarzschild's 1999 principle of AvoidF should be viewed as an instance of Maximize Presupposition! following Truckenbrodt (1995). Chapter 4 deals with intervention effects in German wh-questions. Building on a new empirical generalization, it is suggested that intervention effects are semantic in nature. However, existing semantic proposals such as Beck's 2006 and Kratzer and Shimoyama's 2002 cannot deal with this generalization straightforwardly. Following Chierchia's 2004 analysis of NPI-licensing, it is argued that wh-expressions denote existential quantifiers and introduce domain alternatives. It is suggested that the alternatives of the clausal node differing only in the size of the domains for the existential quantifier must be such that the disjunction of the propositions in the question denotation is equivalent to the ordinary value of the clausal node. In constructions exhibiting intervention effects, the alternatives are not ordered by disjunction, making the question denote the empty set.

Chapter 5 (partly based on joint work with Benjamin Spector) argues for a generalization of Fox's 2000 Scope Economy condition. In particular, it is shown that inverse scope representations are only allowed by the grammar if the resulting interpretation is not stronger than the interpretation without movement. Moreover, it is argued that the theory of scalar implicatures can be used to account for this generalization. It is suggested that the grammar demands that the surface scope interpretation of a given sentence gets strengthened. Moreover, the inverse scope interpretation is only allowed if it does not contradict the strengthened surface scope interpretation.