Children in a given linguistic environment all uniformly acquire their target language, but adult learners of L2 do not. UG accounts for children's uniform linguistic behavior, but it cannot serve a similar role in accounting for adult learners' linguistic behavior. I argue that Epstein etal.'s study does not answer the question of why L2 learners end up with nonuniform and imperfect linguistic competence in learning a second language.

If Epstein et al. are right that adult second language learners have full access to UG, then all of the following should be true: adults should be able to consciously transform their I-Language; adults should be able to transform pidgins into Creoles; adults should be as likely as children to restructure their grammars on the basis of “functional” pressure. All the foregoing are false, however, which seriously calls into question the correctness of their hypothesis.

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)

Our results support the idea that adults have access to the principles and parameters of Universal Grammar (UG), contrary to Epstein et al.'s misrepresentation of our work as involvingpartial access toUG. For both LI and L2 acquisition, functional projections appear to develop in a gradual fashion, but in L2 acquisition there ispartial transferin that the lowest projection (VP) is transferred from the speaker's LI.

Epstein et al.'s theory of SLA is heavily dependent on assumptions about both the nature of the acquisition device and the grammar that it produces. This commentary briefly explores the consequences of an alternative set of assumptions, focusing on the possibility that the acquisition device does not include UG and that syntactic representations do not contain functional projections.

The most compelling evidence for Epstein et al.'s central thesis that adult second language acquisition is constrained by the innate cognitive structures that constrain native language acquisition would be evidence of poverty of the stimulus. Although there are studies that point to such evidence, Epstein et al.'s primary form of argumentation, targetlike performance by second-language acquiring adults, is much less convincing.

This commentary addresses two pervasive misconceptions which emerge in Epstein et al.'s target article: (1) that study of second language acquisition (SLA) began in the mid-twentieth century; (2) that SLA has only recently become able to contribute to linguistic theory. There is abundant historical counterevidence; I argue that (1) and (2) obscure the legitimacy of Epstein et al.'s “full access” hypothesis.

The implications of Epstein et al.'s critical evaluation of much of the existing literature on L2-acquisition extends far beyond the domain they discuss. I argue that similar methodological clarification is urgently needed in analyses of the role of UG in L1-acquisition, as well as in discussions in such seemingly “distant” areas as the study of language change.

The confirmatory nature of the empirical evidence used to establish UG effects in L2 development is considered. Specific issues are also raised concerning the internal validity of Epstein et al.'s findings. It is concluded that the role of UG in adult L2 development will only be established when researchers better understand the interaction between the development of UG-constrained structural knowledge and the development of overall L2 proficiency.

This commentary focuses on whether the full set of categories is available to beginning L2 learners. After critiquing Epstein et al.'s experimental evidence for the presence of functional categories, I outline the results of an experiment involving English speakers learning Japanese as a second language that does indeed point toward the early presence of fuuctional categories.

While child language development theory must explain invariant “success,” foreign language learning theory must explain variation and lack of success. The fundamental difference hypothesis (FDH) outlines such a theory. Epstein et al. ignore the explanatory burden, mischaracterize the FDH, and underestimate the resources of human cognition. The field of second language acquisition is not divided into camps by views on “access” to UG.

Epstein et al. attribute second language learning to the forces of transfer and language universals. They show that transfer is minimally involved in certain types of learning and therefore conclude that universals are involved. However, they forget to consider the important role of learning in second language acquisition.

Epstein et al. take as given that, (1) a hypothetical Universal Grammar (UG) exists that allows children effortlessly to acquire their first language; they then argue (2) that critical or sensitive periods do not block the UG from second language acquisition. Therefore, why can't we all effortlessly “acquire” Tibetan in six months or so? Data concerning the neural bases of language are also noted.

This target article is mostly a presentation of experimental research devoted to the larger issue of the role of Universal Grammar in second language learning. Deliberately excluding the aspects of human cognition that makes second language (L2) so variant, Epstein et al. focus on what the learners may know and how they come to know it. This is the aspect of Epstein et al.'s work which is more limiting, and potentially more interesting.

The range of hypotheses considered is surprising in that the most arguably plausible one is not included: the invariant principles of language are available for life, while the parameters of variation cannot be set after puberty. This hypothesis provides a better explanation than the author's for both the deep similarities and the vast differences between child “language growth” and adult language acquisition.

The evidence that L2 learners have full access to UG is not convincing. The following will be shown: (1) The argument that L2 learners “expect” L2 to have particular properties rests on the conceptual confusion ofhaving the concept of language(in the sense of knowing the meaning of “language”) withhaving accessto UG. (2) The claim that L2 acquisition takes place under the constraints imposed by universal principles lacks empirical support. (3) The assumption that L2 learners assign new parameter values is based (...) on a problematic example and remains unclear. (shrink)

Much second language acquisition (SLA) research confuses the representational and the developmental problems of language acquisition, assuming that attributes of a property theory will explain the transitions between the stages of a psychogrammar, or that induction will explain the properties of the representational systems which encode language. I argue that Principles and Parameter-setting theory deals only with the representational problem, and that induction must play a role in explaining the developmental problem. The conclusion is that both Epstein et al. and (...) the papers they criticize are right; they are just not right about the same issues. (shrink)

In this commentary, I examine the experiment reported by Epstein et al. in section 5. What I show here is that the experiment is so poorly executed that little, if anything, can be concluded from it regarding the role of UG in L2 acquisition.

We argue that the model developed in Epstein et al.'s target article does not explain differences between child first language (LI) acquisition and adult second language (L2) acquisition. We therefore sketch an alternative view, originally developed in Clahsen and Muysken (1989), in the light of new empirical findings and theoretical developments.

The current conception of the relation between UG and the grammar of a language rules out the no-access hypothesis, but does not distinguish between the full-access and partial-access hypotheses. The former raises the issue of why language acquisition in child and adult should be so different. The evidence presented in Epstein et al.'s target article seems inconclusive regarding a choice between hypotheses.

This target article's handling of theory and data and the range of evidence surveyed for its main contention fall short of normal BBS standards. However, the contention itself is reasonable and can be supported if one rejects the metaphor for linguistic competence and accepts that are no more than the way the brain does language.

The target article advanced the null, unified and widely misinterpreted generative hypothesis regarding second language (L2) acquisition. Postulating that UG (Universal Grammar) constrains L2 knowledge growth does not entail identical developmental trajectories for L2 and first language (LI) acquisition; nor does it preclude a role for the L1. In embracing this hypothesis, we maintain a distinction between competence and performance. Those who conflate the two repeat fundamental and by no means unprecedented misconstruals of the generative enterprise, and more specifically, of (...) the empirical content of the null hypothesis regarding L2 linguistic knowledge growth. We hope to have identified certain common goals, the adoption of which might constitute a firm foundation for continued productive interdisciplinary development of contemporary theoretical and experimental L2 acquisition research. (shrink)

Curiously, two central areas are unaddressed by Epstein et al.: (i) L1A–L2A differences; (ii) L2 development. Here, findings relevant to (i) and (ii) – as well as their significance – are discussed. Together these form the basis for contesting Epstein et al.'s “Full Access” approach, but nonetheless analyses of the L2 data argue for UG-constrained L2A. Also discussed is the inadequacy of accounts (like Epstein et al.'s) without an explicit and prominent role for the L1.

The contribution to L2-acquisition which comes from UG is conceptually distinct from that which comes from L1 (or from L1 and L2 jointly), but it is difficult to tease the two apart. The workings of deep, core principles (e.g., locality and subjacency) are so massively evident in L1 and L2 as to be of questionable use in the search for the contribution which is purely of UG.

To what extent, if any, does Universal Grammar (UG) constrain second language (L2) acquisition? This is not only an empirical question, but one which is currently investigable. In this context, L2 acquisition is emerging as an important new domain of psycholinguistic research. Three logical possibilities have been articulated regarding the role of UG in L2 acquisition: The first is the hypothesis that claims that no aspect of UG is available to the L2 learner. The second is the hypothesis that claims (...) that only LI instantiated principles and LI instantiated parameter-values of UG are available to the learner. The third, called the hypothesis, asserts that UG in its entirety constrains L2 acquisition. (shrink)