The book presents a new logical framework to capture the meaning of sentences in conversation. It is based on a richer notion of meaning than traditional approaches, and allows for an integrated treatment of statements and questions. The first part of the book presents the framework in detail, while the second demonstrates its many benefits.

This paper investigates a generalized version of inquisitive semantics. A complete axiomatization of the associated logic is established, the connection with intuitionistic logic and several intermediate logics is explored, and the generalized version of inquisitive semantics is argued to have certain advantages over the system that was originally proposed by Groenendijk (2009) and Mascarenhas (2009).

Information exchange can be seen as a dynamic process of raising and resolving issues. The goal of this paper is to provide a logical framework to model and reason about this process. We develop an inquisitive dynamic epistemic logic , which enriches the standard framework of dynamic epistemic logic , incorporating insights from recent work on inquisitive semantics. At a static level, IDEL does not only allow us to model the information available to a set of agents, like standard epistemic (...) logic, but also the issues that the agents entertain. At a dynamic level, IDEL does not only allow us to model the effects of communicative actions that provide new information, like standard DEL, but also the effects of actions that raise new issues. Thus, IDEL provides the fundamental tools needed to analyze information exchange as a dynamic process of raising and resolving issues. (shrink)

In classical logic, the proposition expressed by a sentence is construed as a set of possible worlds, capturing the informative content of the sentence. However, sentences in natural language are not only used to provide information, but also to request information. Thus, natural language semantics requires a logical framework whose notion of meaning does not only embody informative content, but also inquisitive content. This paper develops the algebraic foundations for such a framework. We argue that propositions, in order to embody (...) both informative and inquisitive content in a satisfactory way, should be defined as non-empty, downward closed sets of possibilities, where each possibility in turn is a set of possible worlds. We define a natural entailment order over such propositions, capturing when one proposition is at least as informative and inquisitive as another, and we show that this entailment order gives rise to a complete Heyting algebra, with meet, join, and relative pseudo-complement operators. Just as in classical logic, these semantic operators are then associated with the logical constants in a first-order language. We explore the logical properties of the resulting system and discuss its significance for natural language semantics. We show that the system essentially coincides with the simplest and most well-understood existing implementation of inquisitive semantics, and that its treatment of disjunction and existentials also concurs with recent work in alternative semantics. Thus, our algebraic considerations do not lead to a wholly new treatment of the logical constants, but rather provide more solid foundations for some of the existing proposals. (shrink)

There is a prominent line of work in natural language semantics, rooted in the work of Hamblin, in which the meaning of a sentence is not taken to be a single proposition, but rather a set of propositions—a set of alternatives. This allows for a more fine-grained view on meaning, which has led to improved analyses of a wide range of linguistic phenomena. However, this approach also faces a number of problems. We focus here on two of these, in our (...) view the most fundamental ones. The first has to do with how meanings are composed, i.e., with the type-theoretic operations of function application and abstraction; the second has to do with how meanings are compared, i.e., the notion of entailment. Our aim is to reconcile what we take to be the essence of Hamblin’s proposal with the more orthodox type-theoretic framework rooted in the work of Montague in such a way that both the explanatory utility of the former and the solid formal foundations of the latter are preserved. Our proposal builds on insights from recent work on inquisitive semantics, and it also contributes to the further development of this framework by specifying how the inquisitive meaning of a sentence may be built up compositionally. (shrink)

In many natural languages, there are clear syntactic and/or intonational differences between declarative sentences, which are primarily used to provide information, and interrogative sentences, which are primarily used to request information. Most logical frameworks restrict their attention to the former. Those that are concerned with both usually assume a logical language that makes a clear syntactic distinction between declaratives and interrogatives, and usually assign different types of semantic values to these two types of sentences. A different approach has been taken (...) in recent work on inquisitive semantics. This approach does not take the basic syntactic distinction between declaratives and interrogatives as its starting point, but rather a new notion of meaning that captures both informative and inquisitive content in an integrated way. The standard way to treat the logical connectives in this approach is to associate them with the basic algebraic operations on these new types of meanings. For instance, conjunction and disjunction are treated as meet and join operators, just as in classical logic. This gives rise to a hybrid system, where sentences can be both informative and inquisitive at the same time, and there is no clearcut division between declaratives and interrogatives. It may seem that these two general approaches in the existing literature are quite incompatible. The main aim of this paper is to show that this is not the case. We develop an inquisitive semantics for a logical language that has a clearcut division between declaratives and interrogatives. We show that this language coincides in expressive power with the hybrid language that is standardly assumed in inquisitive semantics, we establish a sound and complete axiomatization for the associated logic, and we consider a natural enrichment of the system with presuppositional interrogatives. (shrink)

This paper provides a complete characterization of epistemic models in which distributed knowledge complies with the principle of full communication (van der Hoek et al., 1999; Gerbrandy, 1999). It also introduces an extended notion of bisimulation and corresponding model comparison games that match the expressive power of distributed knowledge operators.

Concealed questions are determiner phrases that are naturally paraphrased as embedded questions (e.g., John knows the capital of Italy ≈ John knows what the capital of Italy is). This paper offers a novel account of the interpretation of concealed questions, which assumes that an entity-denoting expression α may be type-shifted into an expression ?z.P(α), where P is a contextually determined property, and z ranges over a contextually determined domain of individual concepts. Different resolutions of P and the domain of z (...) yield a wide range of concealed question interpretations, some of which were not noted previously. On the other hand, principled constraints on the resolution process prevent overgeneration. (shrink)

Modified numerals, such as at least three and more than five, are known to sometimes give rise to ignorance inferences. However, there is disagreement in the literature regarding the nature of these inferences, their context dependence, and differences between at least and more than. We present a series of experiments which sheds new light on these issues. Our results show that the ignorance inferences of at least are more robust than those of more than, the presence and strength of the (...) ignorance inferences triggered by both at least and more than depends on the question under discussion, and whether ignorance inferences are detected in a given experimental setting depends partly on the task that participants are asked to perform. We offer an Optimality Theoretic account of these findings. In particular, the task effect is captured by assuming that in performing an acceptability task, participants take the speaker’s perspective in order to determine whether an expression is optimal given a certain epistemic state, while in performing an inference task they take the addressee’s perspective in order to determine what the most likely epistemic state of the speaker is given a certain expression. To execute the latter task in a fully rational manner, participants have to perform higher-order reasoning about alternative expressions the speaker could have used. Under the assumption that participants do not always perform such higher-order reasoning but also often resort to so-called unidirectional optimization, the task effect finds a natural explanation. This also allows us to relate our finding to asymmetries between comprehension and production that have been found in language acquisition. (shrink)

Traditional logical theories are concerned with the characterization of valid reasoning. For such logical theories, the main object of investigation is the notion of entailment, a notion that is construed as a relation between two or more declarative statements, dictating when one of them can be legitimately inferred from the others. In the course of the previous century, however, and especially since the 1970s, the scope of logical theories has become much broader. In particular, logic is no longer only concerned (...) with declarative statements, but also with questions. Accordingly, the field is no longer focusing exclusively on the entailment relation that may hold between two or more statements, but also aims to characterize fundamental relations that may hold between questions, or between questions and statements. For instance, when does a statement resolve a given question? When does a statement evoke a certain question? And when does the resolution of one question depend on the resolu .. (shrink)

This paper is concerned with constraints on the interpretation of pronominal anaphora, in particular Condition B effects. It aims to contribute to a particular approach, initiated by Reinhart (Anaphora and semantic interpretation, 1983) and further developed elsewhere. It proposes a modification of Reinhart’s Interface Rule, and argues that the resulting theory compares favorably with others, while being compatible with independently motivated general hypotheses about the interaction between different interpretive mechanisms.

This short paper describes a perspective on questions which does not view wh-words as existential quantifiers or as expressions introducing a quantificational domain, but rather as indeterminate referential expressions (Dotlačil and Roelofsen 2019). The proposal is programmatic in nature, and several aspects of it remain to be worked out in greater detail. I argue, however, that it has several potential benefits, including a principled account of weak and strong question interpretations, a uniform analysis of single-wh and multiple-wh questions, and an (...) account of the typologically widespread similarity between interrogative and indefinite pronouns which, unlike previous approaches, can explain the observation that if a language contains interrogative and indefinite pronouns which are similar in form but non-identical (e.g., where and somewhere), the indefinite pronouns are always morphologically more complex than the interrogative pronouns, and never the other way around (Haspelmath 1997). The tentative proposal is that an interrogative pronoun involves complete indeterminacy in the sense that it does not only leave open what its referential value is but also whether it has a referential value at all. For instance, where is completely indeterminate, permitting lack of a referential value. The ‘some’ in somewhere eliminates this possibility and thereby exerts existential force. (shrink)