This chapter discusses some of the causal forces that enable young children to acquire language. It demonstrates that these causal forces are not readily apparent in the input that children experience. This discussion of the causal forces of language and the poverty of the stimulus focuses on just a fragment of human language. The chapter discusses four kinds of expressions. In English, these expressions are the words some, any, and or, and question words such as who and what. Although these (...) expressions appear to be unrelated, the chapter shows that they are all cut from the same cloth – they are governed by the same linguistic principles, which determine both their distributional properties and their meanings. Like any and or, linguists have proposed principles that amalgamate information‐seeking questions and their statement counterparts. The chapter describes the important role played by cross‐linguistic facts as a source of information about the deep forces that shape language. (shrink)

Universal Grammar (UG) is a theory about the innate linguistic knowledge that child language learners bring to the task of language acquisition. This chapter examines the findings of experimental research on children's knowledge of one principle of UG, called Principle C. It presents the defining properties of Principle C. The chapter reviews empirical evidence showing that children apply Principle C to a range of disparate‐looking phenomena. It also presents empirical findings that document children's assignment of hierarchical structure to strings of (...) words. The empirical evidence supports a conclusion – that child language learners access a level of linguistic representation in addition to the constituent structure that is formed using Merge. This additional component of the language apparatus is called Logical Form. The chapter looks at a string of words where Principle C applies at the level of Logical Form. Cleft sentences are one such case. (shrink)

A fundamental goal of linguistic theory is to explain how natural languages are acquired. This paper describes some recent findings on how learners acquire syntactic knowledge for which there is little, if any, decisive evidence from the environment. The first section presents several general observations about language acquisition that linguistic theory has tried to explain and discusses the thesis that certain linguistic properties are innate because they appear universally and in the absence of corresponding experience. A third diagnostic for innateness, (...) early emergence, is the focus of the second section of the paper, in which linguistic theory is tested against recent experimental evidence on children's acquisition of syntax. (shrink)

In just a few years, children achieve a stable state of linguistic competence, making them effectively adults with respect to: understanding novel sentences, discerning relations of paraphrase and entailment, acceptability judgments, etc. One familiar account of the language acquisition process treats it as an induction problem of the sort that arises in any domain where the knowledge achieved is logically underdetermined by experience. This view highlights the cues that are available in the input to children, as well as childrens skills (...) in extracting relevant information and forming generalizations on the basis of the data they receive. Nativists, on the other hand, contend that language-learners project beyond their experience in ways that the input does not even suggest. Instead of viewing language acqusition as a special case of theory induction, nativists posit a Universal Grammar, with innately specified linguistic principles of grammar formation. The nature versus nurture debate continues, as various poverty of stimulus arguments are challenged or supported by developments in linguistic theory and by findings from psycholinguistic investigations of child language. In light of some recent challenges to nativism, we rehearse old poverty-of stimulus arguments, and supplement them by drawing on more recent work in linguistic theory and studies of child language. (shrink)

Over the past forty years, scientists have developed models of human reasoning based on the principle that human languages and classical logic involve fundamentally different concepts and different methods of interpretation. In The Emergence of Meaning Stephen Crain challenges this view, arguing that a common logical nativism underpins human language and logical reasoning. The approach which Crain takes is twofold. Firstly, he uncovers the underlying meanings of logical expressions and logical principles that appear in typologically different languages (...) - English and Mandarin Chinese - and he demonstrates that these meanings and principles directly correspond to the expressions and structures of classical logic. Secondly he reports the findings of new experimental studies which investigate how children acquire the logical concepts of these languages. A step-by-step introduction to logic and a comprehensive review of the literature on child language acquisition make this work accessible to those unfamiliar with either field. (shrink)

We present a series of arguments for logical nativism, focusing mainly on the meaning of disjunction in human languages. We propose that all human languages are logical in the sense that the meaning of linguistic expressions corresponding to disjunction (e.g. English or , Chinese huozhe, Japanese ka ) conform to the meaning of the logical operator in classical logic, inclusive- or . It is highly implausible, we argue, that children acquire the (logical) meaning of disjunction by observing how adults use (...) disjunction. Findings from studies of child language acquisition and from cross-linguistic research invite the conclusion that children do not learn to be logical—it comes naturally to them. (shrink)

This paper investigates young children's knowledge of scalar implicatures and downward entailment. In previous experimental work, we have shown that young children access the full range of truth-conditions associated with logical words in classical logic, including the disjunction operator, as well as the indefinite article. The present study extends this research in three ways, taking disjunction as a case study. Experiment 1 draws upon the observation that scalar implicatures (SIs) are cancelled (or reversed) in downward entailing (DE) linguistic environments, e.g., (...) in the scope of negation (Chierchia, 2000). Experiment 2 was designed to determine if scalar implicatures are used by children, like adults, to influence the interpretation of disjunction in non-DE contexts, yielding an implicature of exclusivity for disjunction. Whereas adult controls always rejected assertions of the form A or B in positive (non-DE) contexts in which assertions of the form A and B were also true, many children accepted assertions with disjunction in such contexts. To provide an interpretation to the findings from Experiment 2, a new experimental technique was devised and used in Experiment 3. The new technique presents pairs of assertions to children, who are asked to judge which assertion is a ‘better’ description of the context. The findings from Experiment 3 demonstrated children's awareness that A and B is more informative than A or B in positive contexts, where both statements are true. Taken together, the findings of Experiments 2 and 3 are compatible with the view that some children lack the computational resources to apply scalar implicatures when a single assertion is presented alone (see Reinhart, 1999). (shrink)

This paper reports the findings from an interconnected set of experiments designed to assess children’s knowledge of the semantic interactions between negation and quantified NPs. Our main finding is that young children, unlike adults, systematically interpret these elements on the basis of their position in overt syntax. We argue that this observation can be derived from an interplay between fundamental properties of universal grammar and basic learning principles. We show that even when children’s semantic knowledge appears to differ from that (...) of adults, the observed differences.. (shrink)

This paper investigates scalar implicatures and downward entailment in child English. In previous experimental work we have shown that adults’ computation of scalar implicatures is sensitive to entailment relations. For instance, when the disjunction operator or occurs in positive contexts, an implicature of exclusivity arises. By contrast when the disjunction operator occurs within the scope of a downward entailing linguistic expression, no implicature of exclusivity is computed. Investigations on children’s computation of scalar implicatures in the same contexts have led to (...) a slightly different picture. In particular it has proven difficult to demonstrate that children compute scalar implicatures (in non- downward entailing contexts) using the Truth Value Judgment task, a technique that has been used successfully in showing children’s sensitivity to other semantic phenomena. Adopting a different experimental technique called the Felicity Judgment task, however, we demonstrated children’s knowledge of the prerequisites to the computation of scalar implicatures (Chierchia, Crain, Guasti, Gualmini and Meroni, 2001). (shrink)

Nativists inspired by Chomsky are apt to provide arguments with the following general form: languages exhibit interesting generalizations that are not suggested by casual (or even intensive) examination of what people actually say; correspondingly, adults (i.e., just about anyone above the age of four) know much more about language than they could plausibly have learned on the basis of their experience; so absent an alternative account of the relevant generalizations and speakers' (tacit) knowledge of them, one should conclude that there (...) are substantive "universal" principles of human grammar and, as a result of human biology, children can only acquire languages that conform to these principles. According to Pullum and Scholz, linguists need not suppose that children are innately endowed with "specific contingent facts about natural languages." But Pullum and Scholz don't consider the kinds of facts that really impress nativists. Nor do they offer any plausible acquisition scenarios that would culminate in the acquisition of languages that exhibit the kinds of rich and interrelated generalizations that are exhibited by natural languages. As we stress, good poverty-of-stimulus arguments are based on specific principles - - confirmed by drawing on (negative and crosslinguistic) data unavailable to children -- that help explain a range of independently established linguistic phenomena. If subsequent psycholinguistic experiments show that very young children already know such principles, that strengthens the case for nativism; and if further investigation shows that children sometimes "try out" constructions that are unattested in the local language, but only if such constructions are attested in other human languages, then the case for nativism is made stronger still. We illustrate these points by considering an apparently disparate -- but upon closer inspection, interestingly related -- cluster of phenomena involving: negative polarity items, the interpretation of 'or', binding theory, and displays of Romance and Germanic constructions in child- English.. (shrink)

There are universals of language; but is it also true, as the target article claims, that there are universals of reading? We believe there are no such universals, and invite others to refute our claim by providing a list of some universals of reading. If there are no universals of reading, there cannot be a universal model of reading.

A recent theory provides a unified cross-linguistic analysis of the interpretations that are assigned to expressions for disjunction, Negative Polarity Items, Free Choice Items, and the non-interrogative uses of wh-phrases in languages such as Mandarin Chinese. If this approach is on the right track, children should be expected to demonstrate similar patterns in the acquisition of these linguistic expressions. Previous research has found that, by age four, children have acquired the knowledge that both the existential indefinite renhe “any” and wh-words (...) in Mandarin Chinese are interpreted as Negative Polarity Items when they are bound by downward entailing operators, but the same expressions are interpreted as Free Choice Items when they are bound by deontic modals or by the Mandarin adverbial quantifier dou “all”. The present study extends this line of research to the Mandarin disjunction word huozhe. A Truth Value Judgment Task was used to investigate the possibility that disjunction phrases that are bound by the adverbial quantifier dou generate a conjunctive interpretation in the grammars of Mandarin-speaking 4-year-old children. The findings confirmed this prediction. We discuss the implications of the findings for linguistic theory and for language learnability. (shrink)

Many experimental investigations of human sentence processing have shown that listeners do not wait until they reach the end of a sentence before they begin to compute an interpretation. Rather, listeners incrementally make commitments to an interpretation as the linguistic input unfolds in real time. A consequence of this property of sentence comprehension is that it sometimes gives rise to so-called garden-path effects. In the presence of a temporary ambiguity, listeners may assign an interpretation that later turns out to be (...) unviable and must, therefore, be abandoned in favor of an alternative interpretation. Various explanations have been proposed to account for garden- path effects that have been documented in certain experimental contexts (Frazier and Rayner, 1982; Trueswell and Tanenhaus, 1994; MacDonald, 1994, among others). One line of research has claimed, however, that the referential contexts in which sentences ordinarily appear often mitigate, or even completely eliminate, garden-path effects. This is the Referential Theory proposed by Crain and Steedman (1985) and extended by Altmann and Steedman (1988). According to the Referential Theory, people experience garden-path effects primarily when sentences are interpreted outside any referential context or in infelicitous contexts. If the Referential Theory is correct, garden-path effects are largely experimental artifacts. Recent work by Trueswell, Sekerina, Hill and Logrip, (1999) suggests that children might not be sensitive to features of the referential context to the same.. (shrink)

Studies of adult sentence processing have established that the referential context in which sentences are presented plays an immediate role in their interpretation, such that referential features of the context mitigate, and even eliminate, so-called ‘garden-path’ effects. Perceivers experience garden path effects almost exclusively when they are attempting to parse locally ambiguous linguistic structures in the absence of context, or in infelicitous contexts. The finding that the referential context ordinarily obviates garden path effects is compelling evidence for the Referential Theory (...) of parsing, advanced originally by Crain and Steedman, (1985) and extended in Altmann and Steedman (1988). Recent work by Trueswell, Sekerina, Hill and Logrip (1999) suggests, however, that children may not be as sensitive as adults to contextual factors in resolving structural ambiguities. This conclusion is not anticipated by the Referential Theory and, worse still, it runs counter to the Continuity Assumption, which supposes that children and adults access the same cognitive mechanisms in processing language (Crain 1991; 2002; Crain and Wexler 2000; Pinker 1984). The purpose of this paper is to reexamine the observations that have led researchers to conclude that children, unlike adults, may lack sensitivity to referential contexts in comprehension in certain circumstances. Adopting a research strategy which we call the method of subtraction, we present evidence that the performance systems of children and adult differ only minimally; that children are sensitive to the referential context; and that children make use of contextual factors to resolve structural ambiguities in on-line sentence interpretation. (shrink)

This study is concerned with the properties of the disjunction operator, or, and the acquisition of these properties by English-speaking children. Previous research has concluded that adult truth conditions for logical connectives are acquired relatively late in the course of language development. With particular reference to disjunction, the results of several studies have led to two claims. First, it has been argued that the full range of truth-conditions associated with inclusive-or is not initially available to children; instead, children are supposed (...) to interpret disjunction using the truth conditions that are associated with exclusive-or (e.g., Beilin and Lust 1975; Braine and Rumain 1981, 1983; Paris 1973). A second, related claim is that even when children respond as if they have access to the complete range of truth conditions, their responses result from the failure to distinguish or from and (Paris, 1973). (shrink)

In this paper, we discuss the findings of two case studies of children’s semantic competence using sentences that contain the universal quantifier every. Children’s understanding of universal quantification, or lack of it, is probably the most controversial topic in current research on young children’s semantic competence. Even among researchers who draw upon linguistic theory in their investigations of child language, there seems to be a general consensus that preschool and even school-age children make ‘errors’ in interpreting sentences with the universal (...) quantifier, and that these ‘errors’ reveal non-adult grammatical knowledge of universal quantification. However, a handful of studies have recently demonstrated children’s knowledge of several aspects of universal quantification, and the present paper adds to that growing body of work. The studies we discuss assess preschool children’s awareness that the two arguments of the universal quantifier have different interpretative properties, because the restrictor of every (NP) is downward entailing, whereas its nuclear scope (VP) is upward entailing. The experimental findings of the present studies are difficult to reconcile on recent analyses that attribute non-adult grammatical knowledge to children. However, the findings fit well with the view that children’s grammars are essentially the same as those of adults, as the Continuity Assumption supposes. (shrink)

Poverty -of-stimulus arguments have taken new ground recently, augmented by experimental findings from th e study of child language. In this paper, we briefly review two variants of the poverty-of-stimulus argument that have received empirical support from studies of child language; then we examine a third argument of this kind in more detail. The case under discussion involves the structural notion of c-command as it pertains to children’s interpretation of disjunction in the scope of negation.

This paper investigates the influence of contrastive stress in resolving potential semantic ambiguities. The sentences under investigation contain the focus operator only. Sentences with only have three main properties: (a) some sentential element is typically in focus, (b) the speaker presupposes that a set of alternatives to the focus element (the contrast set) has previously been introduced in the context; and (c) the speaker makes the assertion that the focus element has some unique property which other members of the reference (...) set lack. Previous literature on focus has concluded that stress plays a role in the interpretation of only-sentences in many natural languages, including English (Rooth, 1992). In processing terms, this suggests that contrastive stress could immediately determine which NP bears the semantic focus (and therefore the NP that presupposes a contrast set in the context). On this scenario, the processing cost associated with contrastive stress should be no greater than the cost associated with neutral stress. (shrink)

Here’s a recipe for one kind of argument from the poverty of the stimulus. To start, present an array of linguistic facts to be explained. Begin with a basic observation about form and/or meaning in some language (or, even better, an observation that crosses linguistic borders). Then show how similar forms and/or meanings crop up in other linguistic phenomena. Next, explain how one could account for the array of facts using domain-general learning mechanisms – such as distributional learning algorithms, ‘cut (...) and paste’ operations or analogy. Follow this by introducing other phenomena that resist explanation on a learning-theoretic account. Make it clear that domain-general learning mechanisms would leave the learner short of the target language or would cause the learner to overshoot, resulting in ‘generalizations’ that are not characteristic of the natural language(s) under consideration. The next step in the recipe is to show how the entire array of linguistic phenomena can be explained using ‘abstract’ principles of Universal Grammar. These principles are not likely to be ‘learned’ because, as just witnessed, the kinds of mechanisms that are offered by learning-theoretic approaches to language development would direct learners away from the target, rather than towards it. This raises the alternative to learning, i.e., innate specification. From that point onward, the proof is in the pudding – the argument should contain an empirical demonstration that children never form the kinds of mistaken generalizations that are anticipated by learning-theoretic accounts of language acquisition. Instead, the argument should be supported by a demonstration that children form the correct generalizations, despite the apparent complexity of the phenomena, and in the absence of supporting evidence in the input. QED. (shrink)

Several recent papers propose that child and adult grammars differ in their underlying representations of universal quantification, e.g., “every” in English. These proposals attempt to explain children’s nonadult responses, in certain circumstances, in response to sentences that contain the universal quantifier. Blaming children’s nonadult behavior on their grammars is questionable, however, in view of the restrictiveness of the theory of Universal Grammar, which tightly constrains the hypothesis space children can navigate in the course of language development. The restrictiveness of the (...) initial state has led to the Continuity Hypothesis, i.e., the proposal that child language can differ from the local language only in ways in which distinct adult languages can differ from each other. Advocates of the Continuity Hypothesis point out that violations of universal constraints in children’s grammars would have far reaching negative consequences, resulting in myriad ‘errors’ by children both in production and comprehension. Before embracing an analysis that involves such violations, therefore, evidence that children make such errors is needed. In this paper, we draw out the implications of a recent account of children’s nonadult interpretation of universal quantification, by Geurts (2004). We demonstrate that children commit few, if any, any of the ‘errors’ that are predicted by the account, beyond the original nonadult behavior that it was specifically designed to explain. Moreover, the proposed analysis of children’s nonadult grammar is demonstrably inconsistent with their proven semantic competence in interpreting a variety of utterances containing the universal quantifier, alone and in combination with other logical expressions (e.g., disjunction, negative determiner phrases, etc.). These findings buttress previous alternative accounts of the observed differences between children and adults, thereby leaving the Continuity Hypothesis unscathed. (shrink)

This study investigates the influence of contrastive stress on the on-line interpretation of ambiguous spoken sentences containing the focus operator only. The pattern of phonological stress was manipulated so as to associate different linguistic expressions with the focus operator only and to invoke different interpretations. Sentences with marked and neutral stress were evaluated relative to visually presented scenes, which depicted a situation consistent with alternative interpretations. Using a head-mounted eye-movement recording system, we measured the processing difficulty associated with phonological stress (...) and subjects’ fixation duration on the various objects in the scenes. Not only was response accuracy superior on sentences with marked stress, as compared to ones with neutral stress, the pattern of fixations revealed earlier resolution of ambiguity in the marked stress condition. The findings suggest that the parser computes multiple interpretations of ambiguous sentences on-line, with marked stress assisting in the rapid resolution of semantic ambiguity. (shrink)

Do children acquire language rapidly, or slowly? From the vantage point of linguistic theory, all normal children could be expected to have full command of a rich and intricate system of linguistic principles in just a few years. Experimental studies of child language, however, paint a different picture of language development: It appears that language learning extends over many years, with children making numerous missteps along the way. Attempts have been made to reconcile theory and data, by looking for features (...) of language development that might impede the emergence of linguistic knowledge, and by looking in more detail at the experimental findings themselves. We begin by reviewing the reasons, based on current linguistic theory, for anticipating the rapid growth of linguistic knowledge in children. Then we turn to the laboratory, to consider both findings that do not sit well with the expectations of linguistic theory, as well as ones that comport well with theory. (shrink)

This study is concerned with the acquisition of the disjunction operator, or, in English. Two mutually inconsistent claims have been made about the acquisition of disjunction. One claim is that the acquisition of the adult truth conditions for logical connectives, including disjunction, is a late and not fully universal, achievement. With particular reference to disjunction, the findings from several studies are interpreted as showing that only the truth conditions associated with exclusive-or are available to young children (e.g., Beilin and Lust (...) 1975; Braine and Rumain 1981, 1983; Paris 1973). There is a related claim, that even when children respond as if they have access to a broader range of truth conditions, namely those associated with inclusive-or, children's adult-like responses are the result of a failure to distinguish or from and (Paris 1973). (shrink)

Much recent research on child language has been inspired by linguistic principles uncovered by linguists working in the generative framework. Developmental psycholinguists have demonstrated young children’s mastery of a variety of linguistic principles; mostly syntactic principles, but also some semantic principles. The present paper contributes to research on the acquisition of semantics by presenting the findings of a new experiment designed to investigate young children’s knowledge of downward entailment, which is a basic semantic property of Universal Grammar. Section 2 describes (...) how downward entailing operators work in natural languages. Section 3 addresses the issue of how a child could master the complex behavior displayed by downward entailing operators across natural languages. That section also reviews the findings of previous research on children’s knowledge of downward entailment. Section 4 presents the new experiment which was designed to investigate whether children’s knowledge of downward entailment extends to one of its logical properties, as illustrated by one of De Morgan’s laws. Section 5 offers some brief remarks on future research. (shrink)

In sentences with internal negation, Free Choice Inferences (FCIs) are cancelled (Chierchia 2013). The present study investigated the possibility that FCIs are negated, not cancelled, by external negation. In previous research, both Mandarin-speaking children and adults were found to license FCIs in affirmative sentences with a modal verb and the disjunction word huozhe ‘or’ (Zhou, Romoli & Crain 2103). The present study contrasted internal versus external negation in sentences that contained all the ingredients needed to license FCIs. Four experiments (...) were conducted using the Truth Value Judgment Task (Crain & Thornton 1998). Experiment 1 tested Mandarin-speaking children and adults using sentences with internal negation, a modal verb and disjunction. As expected, children did not license FCIs; rather, they assigned a ‘neither’ interpretation to disjunction. Also as expected, adults analyzed disjunction as taking scope over internal negation, yielding a ‘not both’ interpretation (Jing, Crain & Hsu 2005). Experiment 1 provided the benchmarks for sentences with external negation in Experiments 2-4. Experiment 2 confirmed that English-speaking adults distinguish between internal and external negation in sentences with disjunction. In Experiment 3, external negation was conveyed by the focus adverb zhiyou ‘only’. External negation eliminated the between-group differences observed in Experiment 1. Both children and adults analyzed external negation as taking scope over disjunction. Experiment 4 tested the effect of external negation on the computation of FCIs. The test sentences only differed from Experiment 1 by using external negation, rather than internal negation. Again, children and adults interpreted the test sentences in the same way. Most importantly, in contrast to Experiment 1 (with internal negation), both groups analysed external negation as negating, rather than cancelling, FCIs. The findings support the distinction between internal and external negation. (shrink)

Here's one way this chapter could go. After defining the terms 'innate' and 'idea', we say whether Chomsky thinks any ideas are innate -- and if so, which ones. Unfortunately, we don't have any theoretically interesting definitions to offer; and, so far as we know, Chomsky has never said that any ideas are innate. Since saying that would make for a very short chapter, we propose to do something else. Our aim is to locate Chomsky, as he locates himself, in (...) a rationalist tradition where talk of innate ideas has often been used to express the following view: the general character of human thought is due largely to human nature. (shrink)

Much recent research on child language has been inspired by linguistic principles uncovered by linguists working in the generative framework. Developmental psycholinguists have demonstrated young children’s mastery of a variety of linguistic principles; mostly syntactic principles, but also some semantic principles. The present paper contributes to research on the acquisition of semantics by presenting the findings of a new experiment designed to investigate young children’s knowledge of downward entailment, which is a basic semantic property of Universal Grammar. Section 2 describes (...) how downward entailing operators work in natural languages. Section 3 addresses the issue of how a child could master the complex behavior displayed by downward entailing operators across natural languages. That section also reviews the findings of previous research on children’s knowledge of downward entailment. Section 4 presents the new experiment which was designed to investigate whether children’s knowledge of downward entailment extends to one of its logical properties, as illustrated by one of De Morgan’s laws. Section 5 offers some brief remarks on future research. (shrink)

In this paper, we discuss the findings of two case studies of children’s semantic competence using sentences that contain the universal quantifier every. Children’s understanding of universal quantification, or lack of it, is probably the most controversial topic in current research on young children’s semantic competence. Even among researchers who draw upon linguistic theory in their investigations of child language, there seems to be a general consensus that preschool and even school-age children make ‘errors’ in interpreting sentences with the universal (...) quantifier, and that these ‘errors’ reveal non-adult grammatical knowledge of universal quantification. However, a handful of studies have recently demonstrated children’s knowledge of several aspects of universal quantification, and the present paper adds to that growing body of work. The studies we discuss assess preschool children’s awareness that the two arguments of the universal quantifier have different interpretative properties, because the restrictor of every (NP) is downward entailing, whereas its nuclear scope (VP) is upward entailing. The experimental findings of the present studies are difficult to reconcile on recent analyses that attribute non-adult grammatical knowledge to children. However, the findings fit well with the view that children’s grammars are essentially the same as those of adults, as the Continuity Assumption supposes. (shrink)

This paper investigates the interaction of prosodic information and discourse principles in child language, taking sentences with the focus operator only as a case study. For adults, prosodic information alone can influence the truthconditional interpretation of (otherwise) ambiguous sentences. However, the findings of two experiments demonstrate that children are not able to use prosodic information alone to resolve certain ambiguities involving the focus operator only. The next section reviews the semantic properties of the focus operator only. Then we review the (...) relevant prior literature on child language, before turning to our own experimental studies. (shrink)

Much current research is devoted to children’s non-adult responses to sentences containing the universal quantifier every. In this chapter we review two alternative views: one that attributes children’s responses to nonadult grammars and one that focuses on extra-linguistic factors to explain children’s non-adult responses. We argue that the grammatical view faces several theoretical concerns, and, in light of research experimental findings, we demonstrate that it also suffers from limited explanatory power.