Agreement, Shells, and Focus Andrew Simpson and Zoe Wu This article reconsiders the development and licensing of agreement as a syntactic projection and argues for a productive developmental relation between agreement and the category of focus. The authors suggest that focus projections are initially selected by a variety of functional heads with real semantic content. Over time however such selected focus frequently decays into a simple concord shell, and when this occurs, the lower half of the shell becomes a simple agreement projection parasitically licensed by the higher functional head, which does have a genuine semantic value.* Introduction In current Chomskyan approaches to syntax, the status of agreement as a functional type projected in syntax has come to be rather controversial. On the one hand, Chomsky (1995) argues that agreement has no particular semantic content and therefore should not project as a functional head. On the other hand, there is much morphological and syntactic evidence in favor of agreement projections, and their existence is still widely assumed in much ongoing work (e.g. Brody 2000, Kayne 1994, Cinque 1999). Attempting to confront this general problem, we set out to establish the suggestions in 1, arguing for a productive developmental relation between agreement and the category of focus: (1) a. Focus may actually occur in more than one syntactic position, contra assumptions implicit in much recent work such as Rizzi 1997. b. Focus may in fact be selected by a variety of functional heads with real semantic content. c. Over time, the focus interpretation of a selected focus projection may decay and become lost. The decay of a focus projection then gives rise to a two-part shell structure in which the lower half of the shell becomes simple agreement or concord and is parasitically licensed by the upper half of the shell, which does have a genuine semantic value. The simple intuition we attempt to establish and make use of is the observation that the repetition effect found in the doubling of morphological material frequently results in natural emphasis, and may be directly triggered by the need to encode focus. Such focus effects may, however, later undergo weakening and eventually result in just simple agreement with two elements relating to a single semantic value. In such an instance, we suggest, agreement as a functional projection then comes to be licensed in a two-part shell structure parasitically, in virtue of the genuine semantic content of the higher shell head. The view of agreement developed here argues that agreement projections do not occur as extended projections of lexical categories, as commonly assumed, but are instead induced and legitimized in syntactic structure by higher functional heads. The article also deals with issues of discontinuous dependencies and the relation of focus to the universal base hypothesis. The term agreement is used in its broadest sense to refer to all instances where properties of one linguistic element are separately coded in a second position in syntactic [End Page 287] structure. Elsewhere in Chomskyean approaches to morpho-syntax there is sometimes a separation of agreement phenomena into instances where the agreement properties of a maximal projection are locally matched against those of a head in a spec-head configuration, i.e. spec-head agreement, and other instances of agreement where elements with corresponding features do not occur in such a relation, often referred to with the term concord. Here we do not assume that spec-head agreement and concord are necessarily different phenomena to be approached and treated in different ways, and there is correspondingly no significant distinction assumed in our use of the terms agreement and concord. We return to the issue of how spec-head and other agreement phenomena may be analyzed in essentially the same way toward the end of the article (§6).1 1. French negative concord The first of the patterns we present as support for the suggestions in 1 is the occurrence of negative concord in French, where two discrete morphemes, ne and pas, signal a single instance of negation, as in 2. (2) When two elements are associated with a single semantic value in this way, the question arises as to how this is actually realized...