AUTHOR: Snyder, William TITLE: Child Language SUBTITLE: The Parametric Approach PUBLISHER: Oxford University Press YEAR: 2007
Aviad Eilam, Department of Linguistics, University of Pennsylvania
SUMMARY This book deals with the acquisition of interlinguistic grammatical variation, construed as differences in the abstract grammatical generalizations the child posits, whether they be in the form of syntactic parameters, phonological constraints, or other possible representations. Examining the acquisition of specific constructions, primarily in spontaneous speech, it aims to demonstrate the significance of research in this domain for understanding how grammatical knowledge is organized.
Following a brief introduction to the book and its general organization in Ch. 1, Ch. 2 (The View from Syntactic Theory) provides an overview of two major syntactic theories, the Principles and Parameters (P&P) framework and Minimalism, and discusses how they approach the issue of crosslinguistic variation. The former views the grammar of a given language as a list of parameter settings, and thus can straightforwardly model such variation. Unfortunately, theoretical work attempting to identify parameters has produced mixed results at best, as Snyder notes, possibly due to the lack of sufficiently detailed analyses of typologically distinct languages. Nonetheless, he proposes to consider P&P from the perspective of acquisition. Assuming that certain constructions are contingent on some grammatical properties, the order in which these constructions are attested in the child's language arguably reveals the way in which the properties are arranged, i.e., the form of the underlying parameter. Specifically, the theory yields two primary acquisitional predictions, labeled concurrent (1) and ordered (2) acquisition (p. 7):
(1) If the grammatical knowledge (including parameter settings and lexical information) required for construction A, in a given language, is identical to the knowledge required for construction B, then any child learning the language is predicted to acquire A and B at the same time.
(2) If the grammatical knowledge (including parameter settings and lexical information) required for construction A, in a given language, is a proper subset of the knowledge required for construction B, then the age of acquisition for A should always be less than or equal to the age of acquisition for B. (No child should acquire B significantly earlier than A.)
These predictions will be tested repeatedly in the following chapters. A more controversial proposal put forward in this section is Snyder's notion of ''grammatical conservatism'' (p.8):
''Children do not begin making productive use of a new grammatical construction in their spontaneous speech until they have both determined that the construction is permitted in the adult grammar, and identified the adult's grammatical basis for it.''
This idea is essential for the use of acquisition data to derive parametric hypotheses, since it rules out the possibility that the child's data reflects a grammar different from that of the adult. Moreover, grammatical conservatism affords the researcher ''clean'', unambiguous data, and a well-defined point in the time course of acquisition from which to begin the analysis. Snyder mentions a number of studies ostensibly supporting the hypothesis of grammatical conservatism, to be discussed in later chapters.
Having surveyed P&P, the book turns to the architecture of the Minimalist Program. In addition to a succinct description of its general characteristics, this portion addresses the issue of crosslinguistic variation within the theory. Snyder presents Chomsky's (1995) original proposal to reduce all variation to features of lexical items, and examines the extent to which various analyses conform to this idea. One analysis which follows Chomsky is Longobardi's (2001) Referentiality Parameter, which derives crosslinguistic variation in the order of determiners, nouns and adjectives from the strength/weakness of the N feature in D. A second attempt at explaining crosslinguistic variation discussed by Snyder is Bobaljik and Thráinsson's (1998) Split IP Parameter. This proposal aims to account for the divide in the Germanic language family between languages which display a certain group of properties, including verb raising out of vP, distinct inflectional affixes for tense and agreement, and multiple positions for subjects and objects, vs. those that do not. It posits that these properties result from the existence of more functional projections between CP and vP in the former group compared to the latter. In other words, the parameterization is in the hierarchy of projections, and not in the information stored in a single lexical item, unlike Longobardi's approach. A third and final account of crosslinguistic variation is Bošković's (2004) DP parameter, as Snyder labels it, which also does not strictly adhere to Chomsky's version of parameterization within Minimalism. Specifically, it links Japanese-style scrambling to the lack of a DP layer above NP, as well as the presence of overt case marking. The acquisitional predictions of this parameter were tested in a study on Korean, reviewed in Ch. 6.
Ch. 3 (The View from Phonological Theory) moves from syntax to phonology, surveying two major phonological frameworks, Optimality Theory (OT) and Government Phonology (GP). The general machinery of OT is first depicted and applied to the example of crosslinguistic variation in syllable structure. Snyder then focuses on the question of learnability, acknowledging that OT is not genuinely compatible with the idea of grammatical conservatism: the ranking of a pair of constraints commits the learner to a resultant ranking of said constraints vis-à-vis other constraints, possibly conflicting with the target grammar. In the latter case, the child is expected to make substantive errors, or errors of comission, rather than just errors of omission, contra the predictions of grammatical conservatism.
The manner in which GP treats the typology of syllable structure is also discussed. This framework fares better with respect to Snyder's claim of grammatical conservatism, since its inviolable constraints can be set independently of one another. Furthermore, its parameters tend to have a subset/superset character, allowing the child to be grammatically conservative by selecting the subset value and thus to avoid possibly erroneous output, until there is sufficient evidence for the superset value.
Ch. 4 (The View from Children's Spontaneous Speech) presents a detailed guide on how data from spontaneous speech can be used in parametric research, focusing on the English corpora available on CHILDES. To illustrate working with these corpora, as well as examine the frequency of errors in child language, a section is devoted to the case study of the English verb-particle construction. Snyder goes through the stages involved in this type of corpus work, including step-by-step directions for computerized searches using CLAN, the software package tailored for CHILDES. Applying his methodology to the verb-particle constructions produced by one English-speaking child, Snyder finds only three errors of comission in the child's 10,233 utterances. He considers the dearth of such mistakes support for the notion of grammatical conservatism. In addition, the data reveals a ''geyser'' effect in the acquisition of high-frequency constructions: infrequent use at first, increasing soon after, and an explosion of examples within a few months.
While the findings reported in Ch. 4 did not require statistical inferences, in most cases conclusions cannot be reached simply by eyeballing the data. Accordingly, Ch. 5 (Statistical Methods for Longitudinal Studies) provides a synopsis of statistical methods needed to test predictions of concurrent and ordered acquisition. It describes the relevant statistical tests, and then demonstrates their use in a study of the acquisition of the verb-particle construction and compounds in English. The theoretical backdrop for this study is The Compounding Parameter (TCP), which reduces the occurrence of verb-particle constructions in a language to the availability of novel endocentric root compounds. This proposal is corroborated by a typological survey: if a language exhibits the former, it necessarily allows the latter, but not vice versa. The acquisitional prediction, whereby compounding will be acquired prior to, or at the same time as, verb-particle constructions, was also borne out: among 19 English-learning children, compounding was never attested later than verb-particle constructions. Moreover, this result held even when mean length of utterance in morphemes, argued to reflect the children's processing capability, was factored out.
Ch. 6 (Experimental and Statistical Methods for Cross-Sectional Studies) turns to experimental methods which can be used to assess parametric hypotheses. The chapter reviews the techniques of elicited production and truth value judgment, examining studies in which they were employed and the conclusions one can draw from them. Although some of these studies have been put forward as evidence that children's grammars are not necessarily identical to those of adults, allowing, for example, left-branch extraction in English, Snyder presents data from both experimental studies and studies of spontaneous speech contesting these claims. Furthermore, he maintains that the productions and interpretations of children in these settings do not always reflect a commitment to the grammar underlying them. In other words, the idea of grammatical conservatism is retained, albeit with the caveat that it may be trumped in certain contexts, such as an experimental task. Experimental methods are nevertheless beneficial for parametric research, provided that they are used to test forms which are assumed to be available to the child at some point.
Following a description of statistical tests which are appropriate for these methods, Snyder illustrates their use in a study of the acquisition of case marking and Japanese-style scrambling in Korean (Kang 2005). Given Bošković's (2004) DP parameter, described in Ch. 2, an ordering effect was predicted, namely, that case marking is acquired before or concurrently with Japanese-style scrambling. Kang indeed found a contingency between these two grammatical options; in fact, only one child exhibited knowledge of case marking but failed on the items testing scrambling. While this result might suggest that case marking is not only necessary, but also sufficient, for scrambling, the fact that languages like Icelandic have the former but not the latter constitutes evidence against such a hypothesis. Thus, Snyder concludes that the other prerequisites for Japanese-style scrambling are acquired earlier than case marking.
Ch. 7 (Case Studies in the Parametric Approach) is devoted to three studies of parametric acquisition using data from spontaneous speech, which Snyder conducted over the past few years with various collaborators. The chapter first describes work on the acquisition of syllable structure in Dutch, done within the theoretical framework of GP, which was surveyed in Ch. 3. The availability of s-initial consonant clusters in word-initial position is derived from the positive setting of two parameters, the Branching Rhyme Parameter, which allows/prohibits branching rhymes, and the Magic Empty Nucleus Parameter, which allows/prohibits an empty nucleus before an s+C sequence. The positive setting of the Branching Rhyme Parameter alone licenses consonant clusters in non-word-initial position; in other words, a subset of the options allowed by the positive setting of both parameters. In terms of acquisition, this hypothesized configuration leads to a prediction of ordered acquisition: branching rhymes will be acquired prior to or concurrently with s+C sequences in word-initial position. The findings matched the prediction: no child learning Dutch produced s+C sequences before producing branching rhymes. The fact that no attested language allows s+C word-initial sequences but not branching rhymes constitutes converging evidence for the hypothesis from the typological domain.
The second study deals with noun-drop (N-drop) in Spanish, which allows speakers to realize a DP without a noun, as in _el azul_ 'the blue one' (cf. its ungrammatical English counterpart *the blue). The goal was to test the relation, postulated by many researchers in the generative tradition, between N-drop and rich overt agreement morphology within the DP. While one Spanish-speaking child produced N-drop as soon as she exhibited mastery of gender and number agreement on determiners and adjectives, another did not; there was a significant gap between the two. Accordingly, Snyder argues that rich agreement is necessary but not sufficient for N-drop, and additional abstract properties are necessary to license the latter.
The third and final case study in this chapter involves preposition-stranding (p-stranding) vs. pied-piping in English and Spanish. This work aimed to determine whether all parameters have a default value with which the child begins the acquisition process, as proposed by Chomsky (2001). If this hypothesis is correct, we expect to find learner errors when the target grammar is the marked value for the parameter, and the initial default value permits grammatical constructions banned by the target grammar. In the case at hand, this derives two possible scenarios: (1) p-stranding is the default value, and hence both English- and Spanish-speaking children should exhibit it initially; (2) pied-piping is the default value, so that English-speaking children are predicted to use this strategy before shifting to the greatly preferred (and perhaps exclusive) option found in the adult grammar, p-stranding. The results did not match either scenario: no Spanish-speaking child exhibited p-stranding, while no English-speaking child used pied-piping. Moreover, a majority of the English learners displayed p-stranding following an extended period in which they used both prepositions and direct object wh-questions, indicating that p-stranding was also not the default for them. Thus, Snyder reasons that not every parameter has a default specification; in addition, the notion of grammatical conservatism is supported by the absence of substantive errors in the children's speech.
Having gone through a range of studies on parametric acquisition, in Ch. 8 (Conclusions: Grammatical Conservatism and Cross-Linguistic Variation) Snyder returns to the fundamental issues raised in the course of the book and summarizes his take on them. He first tackles the question of what the child is acquiring in her first years of life, focusing in syntax on various answers provided by researchers working within Minimalism. As for phonology, Snyder revisits the problem OT poses for grammatical conservatism given the collateral effects of setting a particular ranking for a pair of constraints, but he leaves open the question of whether there are indeed specific cases in which OT predicts errors of comission. The subsequent portion recapitulates the evidence for grammatical conservatism, and also takes into account possible counterexamples, beyond the results of experimental techniques which were already addressed in Ch. 6. For example, Snyder views the optional infinitive stage in children, involving the substitution of an infinitive for the finite verb of a matrix clause, as a maturational phenomenon, rather than an acquisition error. This claim is supported by the fact that children learning a wide variety of languages go through this stage at approximately the same time, but otherwise do not commit to an incorrect grammar (e.g., they place the infinitive in the appropriate clause-final position in German). Nonetheless, Snyder acknowledges that in some domains, such as inflectional morphology, comission errors are more common than in syntax.
Ch. 8 also reviews the acquisitional predictions derived from parametric hypotheses, adding a prediction of earliness to those noted earlier, i.e., concurrent and ordered acquisition. In this case, an underlying link between two constructions, supplied by Universal Grammar (UG), allows the child to deduce that a given construction, when lacking sufficient evidence in the language, is possible based on evidence for the other. We thus predict that rare constructions may be attested early on if they are linked to other, more widespread forms, and indeed Snyder provides experimental evidence for such a claim from Isobe's (2005) work on head internal relative clauses in Japanese. Snyder subsequently situates his type of acquisitional research within the broader field of work on parametric hypotheses, noting the strengths and weaknesses of his and other methods, such as typological studies and second language acquisition. Lastly, he considers the linguistic theory one must postulate in light of grammatical conservatism. According to Snyder, it cannot be of the type proposed by Yang's (2002) variational model, since the latter posits that all possible UG-compatible grammars are available to the child, and hence predicts comission errors. Rather, the ideal model would consist solely of parameters with a subset/superset character, as mentioned in Ch. 3. Unfortunately, many of the parameters proposed in the literature are not of this form; possible solutions to this issue include splitting existing binary parameters into two separate parameters, or assuming that some parameters initially have an ''unset'' value, and grammatical conservatism would follow from the child avoiding utterances that rely on the setting of these parameters.
EVALUATION This book is a clear and elegant summary of the author's research on children's acquisition of grammatical knowledge from a crosslinguistic perspective. Essential techniques for analyzing spontaneous speech data are discussed in depth, complemented by a theoretical point of view which puts forth interesting observations and claims, some of which merit additional consideration. In terms of editing, the book is nearly flawless; I found only a small number of noteworthy typos.
Among the issues which warrant attention is grammatical conservatism, i.e., the hypothesis that the child does not produce a given construction until she has worked out its underlying grammar, necessarily identical to that postulated by adults. In theoretical terms, it is not obvious that this idea is different from the observation known as Baker's paradox (Pinker 1989): children avoid obvious generalizations when these are erroneous under the adult grammar, despite the fact that they otherwise generalize from their input. From an empirical point of view, it is perhaps a tendency, or an ideal, rather than an exceptionless principle. Furthermore, its validity could be construed, at least to some extent, as an artifact of the methodology employed, namely, transcriptions of spontaneous speech. In order to examine the idea, it seems useful to distinguish between two components it includes, which are confounded in the above definition:
(1) Children begin producing a construction only when they have worked out a possible grammatical basis for it. (2) When children produce a construction, it is necessarily derived from the same grammatical basis as that postulated by adults.
While the validity of (1) is widely accepted, given the absence of a ''trial and error'' period among language learners (Crain & Lillo-Martin 1999; but see, for example, Mills 1985 for a description of the variable word order found in the initial stages of the acquisition of German), (2) is highly debatable. Even if it is true that in the general case, the child is a competent learner, eventually reaching the adult grammar (Kroch 2001), this does not entail that the latter grammar is the one used at every stage in acquisition, nor that it is always the one adopted in the end. Moreover, the fact that languages change arguably shows that it is not.
Already in the early days of generative grammar, it was claimed that the grammar of a child and her parents need not be identical (e.g., Andersen 1973). Actual cases substantiating this claim are not abundant, as expected, but do exist; for example, the production of the possessive construction in child Dutch, which is at odds with grammatical conservatism not only due to the unique characteristics found in the children's output, and hence putatively also in their underlying intermediate grammar, but also because there exists variation among the children (van Kampen & Corver 2006). Regardless of the empirical facts, the notion of grammatical conservatism rules out the possibility that children could be the source of language change. This seems particularly problematic for cases of syntactic change triggered by exogenous causes, such as morphological change, since both the morphological change and the more profound syntactic change would have to take place among the adults in order to be carried over to the next generation. The latter type of linguistic innovation, involving reorganization of an underlying grammar, is highly unlikely to occur in adults given the nature of language learning mechanisms following the critical period. As it stands, grammatical conservatism is not compatible with current attempts to resolve the logical problem of language change (Niyogi & Berwick 1995).
Why, then, is there so little data from acquisition corroborating the existence of errors, and why does Snyder fail to find substantive errors in spontaneous speech? First, as just mentioned, all researchers acknowledge that such errors are the exception rather than the norm. Furthermore, the reflex in the output of underlying grammatical differences may be barely detectable, or detectable only when the grammar is applied to a specific set of utterances. Even if the errors exist and are noticeable, transcriptions of spontaneous speech are surely not the best source of evidence for them, since they are both partial and error-prone: as Snyder himself says, ''transcribing child speech is a difficult and uncertain task'' (p. 78). The most detailed documentations of speech involve at most one hour per week of recordings from a child, and the people responsible for their transcription are unavoidably biased, since they all possess the adult grammar. In addition, as Snyder notes, the available spontaneous speech data only allow us to examine the production of high-frequency constructions, so that there may be plenty of errors in low-frequency constructions which we simply miss.
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Mills, A. E. 1985. The acquisition of German. In _The Crosslinguistic Study of Language Acquisition: Volume 1: The Data_, ed. by D. Slobin. Hillsdale, NJ: Lawrence Erlbaum, 141–254.
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ABOUT THE REVIEWER Aviad Eilam is a third year Ph.D. student at the University of Pennsylvania. His research interests include the semantics and acquisition of expletive negation in Hebrew, the Yiddish component in the syntax and semantics of Hebrew, and syntactic issues in Amharic: basic clause structure, left-dislocation and wh-structures.
*Thanks to Charles Yang for helpful discussion.
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