We argue that the detection of entailment and contradiction relations between texts is a minimal metric for the evaluation of text understanding systems. Intensionality, which is widespread in natural language, raises a number of detection issues that cannot be brushed aside. We describe a contexted clausal representation, derived from approaches in formal semantics, that permits an extended range of intensional entailments and contradictions to be tractably detected.

Since Saebø (1985, 2001) drew the attention of formal semanticists to the compositionality problems raised by anankastic conditionals like If you want to go to Harlem, you have to take the A train, a number of authors have proposed analyses tailor-made for such conditionals. We demonstrate that the seemingly puzzling properties of anankastic conditionals in fact show up independently from each other within a wider range of conditionals, which we call 'near-anankastic'. While they do not have the means-of implication typically associated with anankastics, near-anankastics give rise to their own special additional implications. As a crucial ingredient for a unified account, we provide a new analysis of the semantics of the desire predicate in the antecedent -an issue that has not been adequately pursued in the previous literature. We claim that want has an independently motivated reading on which it predicates the existence of an action-relevant preference (Condoravdi & Lauer 2011, Lauer 2013. We then show that the semantically determined interpretation of anankastic and near-anankastic conditionals arises, predictably and compositionally, from a range of interacting factors that are at play in the interpretation of conditional sentences more generally. The special implications associated with each kind of conditional arise pragmatically. Anankastic and near-anankastic conditionals alike turn out to be just what they seem: regular, hypothetical, indicative conditionals.

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In late Medieval Greek and many modern dialects, pronominal clitics are syntactically adjoined to an IP projection. In another set of dialects they have become syntactically adjoined to a verbal head. In the most innovating dialects (which include Standard Greek) they are agreement affixes. Extending the Fontana/Halpern clitic typology, we propose a trajectory of lexicalization from X max clitics via X 0 clitics to lexical affixes. The evolution of clitic placement also reveals the rise of a composite functional projection ΣP.

Determining whether a major societal event has already happened, is still ongoing , or may occur in the future is crucial for event prediction, timeline generation, and news summarization. We introduce a new task and a new corpus, EventStatus, which has 4500 English and Spanish articles about civil unrest events labeled as PAST, ONGOING , or FUTURE. We show that the temporal status of these events is difficult to classify because local tense and aspect cues are often lacking, time expressions are insufficient, and the linguistic contexts have rich semantic compositionality. We explore two approaches for event status classification: (1) a feature-based SVM classifier augmented with a novel induced lexicon of future-oriented verbs, such as "threatened" and "planned", and (2) a convolutional neural net. Both types of classifiers improve event status recognition over a state-of-the-art TempEval model, and our analysis offers linguistic insights into the semantic compositionality challenges for this new task.