Standard English is typically described as a double negation language. In double negation languages, each negative marker contributes independent semantic force. Two negations in the same clause usually cancel each other out, resulting in an affirmative sentence. Other dialects of English permit negative concord. In negative concord sentences, the two negative markers yield a single semantic negation. This paper explores how English-speaking children interpret sentences with more than one negative element, in order to assess whether their early grammar allows negative concord. According to Zeijlstra's (2004) typological generalization, if a language has a negative syntactic head, it will be a negative concord language. Since Standard English is often analysed as having a negative head, it represents an apparent exception to Zeijlstra's generalization. This raises the intriguing possibility that initially, children recognize that English has a negative head (i.e., n't) and, therefore, assign negative concord interpretations to sentences with two negations, despite the absence of evidence for this interpretation in the adult input. The present study investigated this possibility in a comprehension study with 20 3-to 5-year-old children and a control group of 15 adults. The test sentences were presented in contexts that made them amenable to either a double negation or a negative concord interpretation. As expected, the adult participants assigned the double negation interpretation of the test sentences the majority of the time. In contrast, the child participants assigned the alternative, negative concord interpretation the majority of the time. Children must jettison the negative concord interpretation of sentences with two negative markers, and acquire a double negation interpretation. We propose that the requisite positive evidence is the appearance of negative expressions like nothing in object position. Because such expressions exert semantic force without a second negation, this informs children that they are acquiring a double negation language.

Negative sentences with epistemic modals (e.g., John might not come/John can not come) contain two logical operators, negation and the modal, which yields a potential semantic ambiguity depending on scope assignment. The two possible readings are in a subset/superset relation, such that the strong reading (can not) asymmetrically entails the weak reading (might not). In this situation, a potential learnability issue arises. Based on the Semantic Subset Principle, we anticipated that children's initial interpretations would sometimes differ from those of adults because children are expected to initially prefer strong (can not) readings for sentences that convey weak (might not) readings for adults. This proposal is investigated in two experiments using Standard Italian, which is an ideal testing ground for child language, in view of its simple modal paradigm. The results of these experiments confirm the predictions of the Semantic Subset Principle. Five-year-old Italian-speaking children were found to strongly favor the scope assignment that generates strong (can not) readings, even in cases where adults strongly favor the weak (might not) scope assignment. This result is discussed in relation to some recent alternative proposals (Gualmini & Schwarz, 2009; Musolino, 2006) that do not assume any initial bias toward the strong readings. © Taylor & Francis Group, LLC