Clahsen and Felser (CF) review ground-breaking work comparing selected types of language processing in monolingual children and adults, on the one hand, and in monolingual first language (L1) adults and adult second language (L2) learners, on the other. They argue that children behave essentially like adults, but that adult L2 learners, even high-proficiency ones, do not. Thus, there is a principled difference to be made among types of learners; there is continuity of mechanism and process to be observed in monolingual development but L2 acquisition exhibits certain fundamental differences. In particular, L2 learners construct shallow syntactic structures (essentially failing to compute trace chains) when processing long-distance filler-gap dependencies. According to the shallow structure hypothesis (SSH), learners immediately interpret incoming words in a minimal semantic representation by assigning thematic roles to argument expressions and associating modifiers to their hosts. They are not mapping detailed and complete syntactic representations onto semantic representations.

This study explores influences on bilingual children's phonological awareness (PA) performance in English, examining the role of language of instruction and vocabulary. English monolingual and Spanish–English bilingual kindergartners and first graders receiving either English or Spanish literacy instruction were assessed in English PA and in English and Spanish vocabulary, as appropriate. Spanish-instructed bilinguals were more likely than English-instructed bilinguals or English monolinguals to treat diphthongs as two units, reflecting their analysis in Spanish phonology and orthography. Surprisingly, unbalanced bilinguals dominant in either English or Spanish scored better on English PA than children with approximately equal scores on the English and the Spanish vocabulary test. This finding suggests that familiarity with many lexical items within a language constitutes a source of analyzable phonological knowledge.

Our understanding the relationship between verbal short-term memory as indexed by nonword repetition and word learning must now incorporate myriad factors that were not as apparent 17 years ago when Gathercole and Baddeley (1989) proposed that “the phonological memory skills tapped by nonword repetition play a causal role in vocabulary development” (p. 211). In particular, successful nonword repetition involves more than the phonological loop, word learning happens by degrees, and is influenced by many factors other than phonology, and children with specific language impairment (SLI), who have served as test cases by virtue of consistently demonstrating phonological memory deficits, often exhibit other deficits with the potential to negatively impact word learning. Gathercole (2006) still makes the case for temporary phonological storage playing an important role in word learning, but with several caveats. I would like to add two.

Can fluency in oral reading be facilitated by formatting text to preserve major syntactic boundaries? Seven-, 8-, and 9-year-old children read aloud passages under two text format conditions. In the structure-preserving condition, the ends of lines coincided with ends of clauses; in the phrase-disrupting condition, line breaks always interrupted a phrasal unit. Experiment 1 showed that oral reading fluency, as indexed by skill in phrasal reading, was rated higher when children were reading in the structure-preserving condition. In addition, the structure-preserving condition resulted in significantly fewer false starts at the beginning of lines following a return sweep. The results of Experiment 2, in which texts of varying levels of difficulty were read by slightly older readers, confirmed both findings. Measures of fluency were correlated with other language and reading measures; however, no effects of format were obtained on oral reading rate (words correct per minute). Taken as a whole, these findings indicate a benefit of keeping clausal units intact in promoting fluent reading by facilitating the transition from one line to the next.

Ever since the derivational theory of complexity (DTC) apparently bit the dust in the late 1960s, experimental psycholinguistics have been afflicted by a dualism at least as troublesome as the mind/brain dichotomy, namely, the grammar/parser distinction. The idea that mentally represented grammar is something fully dissociated from the human language processor is less than compelling, yet it has implicitly informed much of the last half century's psycholinguistics practice on both sides of the formalist–functionalist divide.

This study investigates three aspects of social communication in 12-month-old infants and their caregivers: (a) caregiver conversational style, (b) caregiver gesture, and (c) infant engagement. Differences in caregiver behavior during passive joint engagement were associated with language outcomes. Although total mean duration of infant time in passive joint engagement was negatively associated with later language, caregiver contingent comments (CCCs) addressed to infants during passive joint engagements related to language learning. CCC utterances were found to co-occur with gesture, suggesting that CCC is an inherently multimodal conversational style. The positive association between CCCs during passive joint engagements and later language suggests that caregiver behavior is important, even at times when infants are not actively engaged with the caregiver.

The proposals that (a) nonword repetition and word learning both rely on phonological storage and (b) both are multiply determined are two of the major foci of Gathercole's (2006) Keynote Article, which marshals considerable evidence in support of each. In my view, the importance of these proposals cannot be overstated: these two notions go to the heart of the relationship between nonword repetition and word learning. Indeed, they figure prominently in the approach that my colleagues and I have taken to studying that relationship (e.g., Gupta, 2006; Gupta, Lipinski, Abbs, & Lin, 2005; Gupta & MacWhinney, 1997). An important aspect of our approach has been the attempt to construct a computational model that can simulate performance in a nonword repetition task and in a word learning task, the rationale being that a computational model that achieved this would constitute a proposal about the processing mechanisms that may underlie the relationship. In this Commentary, I describe how our computational work offers a concrete way of thinking about how nonword repetition and word learning may rely on phonological storage, and about how these abilities may be multiply determined. Such computational work is, I suggest, a valuable tool in further investigating the important relationship that has been revealed by Gathercole's influential work, and that is analyzed in the Keynote Article.

In two experimental training studies we examined the hypothesis that an emphasis on the meaning of a word is more effective than merely focusing on the orthography to increase reading fluency. Reading delayed children from Grade 1 (mean age = 7.3 years) and two groups from Grade 2 (mean age = 8.3 and 7.8 years) repeatedly read words while focusing either on the orthography or on the semantics of the word. Furthermore, the claim that limited exposure duration during training further promotes fluency was examined. The results show that the semantic based exercises yield more effect than orthographic training, especially for Grade 2 students. No beneficial effect is found for limited presentation duration. The results strongly suggest that practice with printed words with a specific focus on the semantic characteristics effectively promotes the attainment of reading fluency.

Understanding the mechanisms learners use to process target language input is crucial to developing a complete model of both first language (L1) and second language (L2) acquisition. If adult L2 learners are found to process the target language with mechanisms that differ from those used by child L1 learners and adult native speakers, what implications might this have for the developing grammar? Clahsen and Felser review evidence that appears to point to such differences, generalizing their findings under a shallow structure hypothesis about how adult learners process input in L2.

The production of passive sentences by children with specific language impairment (SLI) was studied in two languages, English and Cantonese. In both languages, the word order required for passive sentences differs from the word order used for active sentences. However, English and Cantonese passive sentences are quite different in other respects. We found that English-speaking children with SLI were less proficient than both same-age and younger typically developing peers in the use of passives, although difficulty could not be attributed to word order or a reliance on active sentences. Cantonese-speaking children with SLI proved less capable than same-age peers in their use of passive sentences but at least as proficient as younger peers. The implications of these cross-linguistic differences are discussed.

This Commentary supports Gathercole's (2006) proposal on a double deficit in children with specific language impairment (SLI). The author suggests that these children have a limited phonological storage combined with a particular problem of processing novel speech stimuli. According to Gathercole, there are three areas of skill contributing to memory for nonwords: general cognitive abilities, phonological storage, and an unidentified skill specific to nonword repetition. The focus of this Commentary is to examine whether these children's nonword repetition performance is influenced by an unidentified skill or some other processes. An alternative hypothesis is that the nonword repetition errors observed in children with SLI are related to one of their main weaknesses, to their difficulties in simultaneous processing of information. Evidence for this argument comes from our recent studies: from error analyses data and from findings on nonword repetition with stimuli that included meaningful parts (monosyllabic real words).

This study compared monosyllabic word recognition in quiet, noise, and noise with reverberation for 15 monolingual American English speakers and 12 Spanish–English bilinguals who had learned English prior to 6 years of age and spoke English without a noticeable foreign accent. Significantly poorer word recognition scores were obtained for the bilingual listeners than for the monolingual listeners under conditions of noise and noise with reverberation, but not in quiet. Although bilinguals with little or no foreign accent in their second language are often assumed by their peers, or their clinicians in the case of hearing loss, to be identical in perceptual abilities to monolinguals, the present data suggest that they may have greater difficulty in recognizing words in noisy or reverberant listening environments.

In her Keynote, Gathercole (2006) provides a comprehensive review regarding the nature of the nonword repetition (NWR) task and a compelling argument for the utility of the task as a robust index of children's phonological short-term storage capacity. She further argues that temporary phonological storage acts as a primitive learning mechanism that plays an instrumental role in the lexical learning of young children, including children with specific language impairment (SLI). In this Commentary, we focus our remarks on two related themes concerning the relation of NWR and SLI: (a) performance on NWR tasks provides a window into these children's more general cognitive (dis)abilities and (b) the robustness of NWR as a predictor of these children's lexical knowledge and learning abilities.

Clahsen and Felser (CF) have written a fairly comprehensive review of the current literature on on-line second language (L2) processing, presenting data from eye movement, self-paced reading, and event-related potential (ERP) studies with the aim of evidencing possible differences between native language (L1) and L2 processing. The thrust of the article, in regard to adult L2 processing, is apparently an attempt to gather evidence to bolster their argument about “shallow processing” in adult L2 learners. Although the authors provide the reader with a generally good overview of the current literature, their argumentation seems to be flawed at times. Consider, first, the authors' presentation of recent ERP evidence. The authors claim that L2 adult learners may lack automaticity in comparison to native speakers in regard to syntactic processing. This is based upon a delayed N400 response, often found in L2 learners compared to native speakers, as well as by the pattern of anterior negativities to morphosyntactic violations. Later, however, this line of argumentation is seemingly undermined. First, as CF rightly underline, the range of variability in anterior negativities found in L2 learners falls within the range of variation observed in native speakers. As such, variability in this response cannot be taken as a marker of differential processing specific to (shallow) syntactic processing in the second language (see also Frenck-Mestre, 2005; Osterhout et al., 2004). Second, as CF later note, the N400 (as well as P600) is systematically observed in adult L2 learners, and is often highly similar to that found for native speakers. Consider, next, the behavioral evidence cited by CF on adult L2 syntactic processing. The authors cite work on various structures, notably relative clause attachment (which has received a great deal of attention in both monolingual and L2 studies). Concerning this structure, although CF cite studies, which show both clear L1 influence on L2 processing and differential effects as a result of experience with the L1, they favor studies that fail to show such effects and reject Mitchell et al.'s (2000) tuning hypothesis as an explanatory model. (Note Mitchell and colleagues have indeed produced evidence of their own showing limitations of their model.) It is also noteworthy that CF's argumentation about the sensitivity of the measure they used to test for immediate preferences for this structure is not as strong as it could be. Indeed, where they report L2 preferences (for low attachment following thematic prepositions), the literature shows the same systematic preference independent of the language tested (cf. Mitchell et al., 2000). As such, the sensitivity of their measure may not be adequately demonstrated. In sum, although CF provide the reader with an impressive collection of current L2 studies, the viewpoint that they espouse does not seem to be as substantiated as they wish to claim.

Traditional models of human memory have postulated the need for a brief phonological or verbatim representation of verbal input as a necessary gateway to a higher level conceptual representation of the input. Potter has argued that meaningful sentences may be encoded directly in a conceptual short-term memory (CSTM) running parallel in time to such a phonological store. The primary aim of the current study was to evaluate two main tenets of the CSTM model: that linguistic context biases selection of information entering the conceptual store, and that information not integrated into a coherent structure is rapidly forgotten. Results confirmed these predictions for spoken sentences heard by both young and older adults, supporting the generality of the model and suggesting that CSTM remains stable in normal aging.

Susan Gathercole's Keynote Article (2006) is an impressive summary of the literature on nonword repetition and its relationship to word learning and vocabulary size. When considering research by Mary Beckman, Jan Edwards, and myself, Gathercole speculates that our finding of a stronger relationship between vocabulary measures and repetition accuracy for low-frequency sequences than for high-frequency sequences is due to differences in the range of the two measures. In our work on diphone repetition (e.g., Edwards, Beckman, & Munson, 2004; Munson, Edwards, & Beckman, 2005) we tried to increase the range in our dependent measures by coding errors on a finer grained scale than simple correct/incorrect scoring would allow. Moreover, restriction of range does not appear to be the driving factor in the relationship between vocabulary size and the difference between high- and low-frequency sequence repetition accuracy (what we call the frequency effect) in at least one of our studies (Munson et al., 2005). When the children with the 50 lowest mean accuracy scores for high-frequency sequences were examined, vocabulary size accounted for 10.5% of the variance in the frequency effect beyond what was accounted for by chronological age. When the 50 children with the highest mean accuracy scores for high-frequency sequences were examined (a group in which the range of high-frequency accuracy scores was more compressed, arguably reflecting ceiling effects), an estimate of vocabulary size accounted for only 6.9% of the frequency effect beyond chronological age. The associated β coefficient was significant only at the α<0.08 level. This is the opposite pattern than Gathercole's argument would predict.

In their target article, Clahsen and Felser (CF) review studies that they and others have conducted in recent years to confirm the dual mechanism hypothesis and to extend its application to first and second language (L1 and L2) learners. They interpret the findings as supporting both the dual mechanism hypothesis and the claim that the sentence-level processing of L2 but not L1 learners shows “striking” differences compared to adult native speakers. I argue that an exclusive focus on the representation of linguistic knowledge is insufficient for understanding the real-time processes in morphological production and sentence comprehension.

The first report of a connection between vocabulary learning and phonological short-term memory was published in 1988 (Baddeley, Papagno, & Vallar, 1988). At that time, both Susan Gathercole and I were involved in longitudinal studies, investigating the relation between nonword repetition and language learning. We both found a connection. Now, almost 20 years later, in her Keynote Gathercole (2006) reviews a multitude of data bearing on the interpretation of this often replicated connection. Her main conclusions are three. First, both nonword repetition and word learning are constrained by the quality of temporary storage. She sees this storage as multiply determined, that is, affected by factors like perceptual analysis, phonological awareness (ability to identify and reflect on the speech sounds that make up words). Second, both nonword repetition and word learning are also affected by sensory, cognitive, and motor processes. Third, an impairment of phonological storage is typically associated with specific language impairment (SLI) but may not be a sole causal factor.

The article by Clahsen and Felser (CF) on grammatical processing in language learning is a timely and much-needed synthesis of research on this topic. It correctly identifies both morphological processing and syntactic processing as key areas that require attention. This commentary raises two issues: the relationship between the grammar and the parser, and the need for a transition theory in adult second language (L2) learning.

This paper does a fine job of advancing discussion concerning a question that is indeed quite underrepresented in the literature, that is, how language learners comprehend and produce language in real time. The paper is firmly rooted in the dual mechanism approach to language processing and takes as its starting point the assumption that normal adult processing is characterized by two systems, one that is lexically based and one that is essentially combinatorial. The authors cite evidence that both first language (L1) learners and adult native speakers show evidence of dual mechanism processing and that, in particular, children's sentence processing shows early reliance on structure-based interpretation and less ability to employ lexical/pragmatic information in the resolution of language ambiguity. One way to view this preference is that L1 learners might know, broadly speaking, considerably more about their language than they do about the world in which they live. Adult second language (L2) learners might be said to be in exactly the opposite situation. It is therefore hardly surprising that adult L2 speakers rely strongly on lexical/pragmatic cues in sentence processing. In the early stages of adult L2 acquisition, the demands of real-time processing make use of such nonsyntactic inference crucial. The question that strikes me as key is whether, as L2 speakers become more proficient, they are weaned from this reliance such that their processing reflects the interaction between syntactic and lexical processing that is characteristic of adult native speakers. When and if they do, we could say that their L2 processing is, both internally and externally, nativelike.