In two experiments we tested the hypothesis that children have a basic problem in mastering the attributive relation because it involves a two-step logical–semantic integration process of the head-noun and the attributive adjective. Hebrew-speaking children were asked to interpret highly familiar adjective–noun combinations by selecting a photo that depicted the correct referent. In Experiment 1 there were four choices for each adjective–noun pair: correct object/correct property, correct object/wrong property, wrong object/correct property, wrong object/wrong property. 170 children (1;6–4;4) participated. Analyses of errors and spontaneous self-corrections indicated that children initially ignored the adjective and based their responses only on the noun. In Experiment 2, in addition to the 4-choice condition, there were two simpler conditions with only two choices: the correct object/correct property, and either the correct object/wrong property, or the wrong object/correct property. 30 children (1;9–4;11) were tested. The children, and in particular the lowest-scoring third of the sample, did significantly better in the 2-pictures conditions. The results suggest that young children do possess a basic adjective vocabulary and can use it in simple discriminations, but have a considerable difficulty in integrating the information furnished by the adjective with information furnished by the noun.

Williams syndrome (WS) is often cited as the prime example within developmental disorders of the dissociation of language from other cognitive skills, particularly from visuo-motor skills. This claim has been responsible for the challenges posed by this population to cognitive theories and to models of language acquisition. Two Hebrew-speaking children with WS were followed longitudinally for 18 months, from the first occurrences of two word combinations. Y was 3;9–5;3 and BT was 4;2–5;8 during data collection. Both children had an MLU of 1·8–2·8. The children's linguistic profiles were compared to the profiles of typically-developing (TD) children of similar MLU as well as to the profiles of 11 children with a variety of neurodevelopmental disorders (ND), matched on MLU. The profiles exhibited by the children with WS throughout the period of the study differed from the profiles seen in both control groups.

A set of tri-zygotic quadruplets, three girls and one boy, participated in weekly observations from 1;2 to 1;10 (years;months), a period of transition from prelinguistic gesture to 50 words. In the study, one girl served as a genetic mate to her identical twin and a biological risk mate to her fraternal sister. The biological risk mates achieved milestones in lexical development at similar times; however, the genetic mates demonstrated more similarities in pattern of lexical development and in the modality of their word productions. Degree of similarity changed over the observation period. Imposed upon the natural experiment was a within-subject manipulation of the social environment: The experimenters modelled a core vocabulary via the gesture+verbal modalities to the children during each visit. The modelling resulted in increased rates of word learning for three of the children; the child with the greatest biological risk, the boy, derived the greatest benefit. The findings provide unique support for a dynamic, multi-factorial model of lexical development involving the interaction of genetics, the biological environment and the social environment. Furthermore, they illustrate the robustness of early lexical development in the face of biological risks.

The paper examines two types of texts, personal experience narratives and expository discussions, dealing with the shared theme of interpersonal conflict. Both were produced by the same 80 subjects, participants in a crosslinguistic study on developing literacy: gradeschoolers aged 9;0 to 10;0, twelve-to-thirteen-year-old junior high school students, sixteen-to-seventeen-year-old high school students, and graduate-level university students. The study reported here aims to demonstrate that inter-genre differentiation is evident from an early age and is reflected by distinct forms of expression across different interlocking linguistic systems. In keeping with the focus on relations between linguistic forms and discourse functions that motivates our study, we further aim to show how particular grammatical elements can fulfil different discourse functions across development. To this end, we analysed several different lexical and morphosyntactic constructions in 160 Hebrew-language texts as diagnostic of inter-genre distinctiveness: subjectless constructions; verbless copular clauses; verb types and the temporal categories of verb tense and mood, including lexical expressions of modality in the two genres. Results show that narratives are clearly distinguished from expository texts along all these dimensions; these distinctions are evident from the youngest age group we considered; and with age, inter-genre differentiation emerges as more moderately dichotomous. We concluded from this that maturely proficient text construction is able to combine expository-type generalizations with narrative event-description and to intersperse narrative-type illustrative episodes with expository formulation of ideas.

Although words have both denotative and connotative meanings, there has been little research on the child's acquisition of connotations. In large segments of written texts, connotations can be studied by examining word co-occurrences (collocations). Using this technique, corpus linguists have found, for example, that ‘happen’ has a negative connotation; it most often collocates with negative words (e.g. ‘accidents’, ‘something dreadful’). The current research is a case study of the use of the lemma ‘happen’. Adult production of ‘happen/happens/happening/happened’ was examined in 151 American English-speaking, adult–child dyads from the CHILDES database. Within these dyads, 35 children used ‘happen’ and its variants. Both adults and children were increasingly likely to use ‘happen’ to describe negative contexts as children's language progressed from MLUs around 1·00 to MLUs greater than 4·00. Results are consistent with usage-based theories of language that claim that the relative frequency of information in the input is critical to language learning.

The study deals with children's use of the connective and to end a story. One hundred and ninety-one children (aged 7;0 to 11;0) who were native speakers of French told two-character comic strip stories with no text to a same-age peer. In the consecutive-display condition, the comic strip was in booklet format with one frame per page, whereas in the simultaneous-display condition, all frames were on the same page. In the arbitrary-sequence condition, the events in each comic strip, although presented as a sequence, could have occurred in any order, whereas in the ordered-sequence condition, the order of the events could not be changed. In the maintained-topic condition, the materials were designed to induce a thematic subject right after the first frame (by the repeated presence of the same character in every picture, up to and including the last one), whereas in the changed-topic condition, the other character appeared alone in the last frame.

The analysis focused on cases where the children began the narration of the last frame using and to change the text pattern established so far. The results showed that and was often used in this way (35·2% of the productions), especially in the experimental conditions that facilitated event interconnection (simultaneous display, ordered sequence, maintained topic). The ordered-sequence condition showed that the nine-year-olds in simultaneous display employed and in co-occurrence with another connective, whereas the eleven-year-olds mainly used and more specifically: when the topic changed. The discussion deals with the specialization during development of the use of and within a speaker's discourse.

Crain, S. & Thornton, R. Investigations in Universal Grammar. Cambridge: MIT, 1998.

Stephen Crain (C) & Rosalind Thornton (T) have garnered a well-deserved reputation for their unwavering commitment to language learnability as a constraint not only on theories of child language and language development but also on experimental design and the interpretation of experimental findings. In his well-known defense of children's early knowledge of syntactic constraints, Crain (1991) argued for the widely-held position that the best solution to the learnability problem is to assume that grammatical knowledge which cannot be learned on the basis of experience is specified in advance as part of the human biological endowment for language in the form of a UNIVERSALGRAMMAR (UG) (Chomsky, 1965). With respect to experimental design, C&T have strongly maintained that even young children know UG constraints but perform poorly in some experiments-due to the extralinguistic demands associated with experimental tasks, particularly those involved in presupposition accommodation and complex response planning. C&T specifically design their experiments to reduce the impact of extralinguistic demands on children's linguistic performance while at the same time providing felicitous environments for adultlike performance.

Crain & Thornton (1998: 5) are admirably clear in stating the aims of their research programme: they ‘hope to convince a greater number of students and researchers in child language of the correctness of the Innateness Hypothesis and the theory of Universal Grammar’. As Drozd notes, however, their assumptions under Modularity Matching ‘set the stage for a research programme unlike those typically adopted by developmental psycholinguists’. Whereas C&T are avowedly committed to the continuity assumption (clearly preferring ‘special nativism’ over ‘general nativism’; O'Grady, 1997), constructivists are more interested in the question of how children ‘get from here to there’ (Tomasello, 2003) – that is, from immature levels of language comprehension and use to adultlike levels (and, it is important to note that adultlike levels are not always characterized in generativist terms). Most constructivists are also committed to studying the relations between language development and other simultaneously developing social and cognitive skills (Clark, 2003), whereas nativists tend to be interested in ‘pure’ linguistic ability uncontaminated by nonlinguistic influences. The main goal of nativists then is to verify a specific theory of linguistic competence that suggests that linguistic knowledge is innate and modular and to account for children's linguistic development in terms of UG, whereas the main goal for constructivists is to account for development (change) in the child's language system (beginning from perhaps no predetermined linguistic knowledge) and how it relates to other aspects of development. It is this fundamental difference in goals that makes one quite pessimistic that constructivist and nativist researchers in syntactic development can learn anything from one another; they are simply engaged in separate tasks.

In his review of Crain & Thornton's (C&T) (1998) Investigations in Universal Grammar (IUG), Drozd raises many substantial concerns that call into question the correctness and usefulness of the Modularity Matching Model, and the adequacy of the experimental designs put forth to support it. My comments will focus on Modularity Matching. First, I elaborate on Drozd's suggestion that C&T's comparisons between Modularity Matching and other (potential) models do not provide convincing support for their model. Second, I suggest that Modularity Matching, while a strong claim, considers such a narrow range of phenomena in child language that its usefulness in explaining language development in general is likewise constrained.

It is not unusual for developmental psychologists to become frustrated with the theory of universal grammar (UG), whose proponents have tended to dismiss most research on children's language production and comprehension as irrelevant to explaining how human languages are acquired. This is because children's actual linguistic behaviour is presumed to reflect factors besides their grammatical competence, rendering most methods of sampling linguistic behaviour unsuitable for evaluating UG theory. This means, in practice, that UG proponents do not view performance errors as evidence against their hypothesis that grammatical knowledge is largely innate. When children perform at ceiling on a given task, this is usually taken as proof of their adultlike grammatical competence, while poor performance is dismissed as due to research design flaws or limitations in information processing capacities (e.g. working memory). Crain & Thornton (1998) attempt to eliminate what they consider to be post hoc processing accounts of children's linguistic behaviour by arguing, counter to Chomsky (1965) and many others, that children and adults share identical language processing mechanisms, and that linguistic performance directly reflects grammatical competence. Therefore, if UG principles are available from an early age, child and adult performance should be the same when tasks are properly constructed to avoid extra-linguistic demand characteristics (excepting adult–child differences predicted by parameter-setting or maturational models). It should not be surprising then that some psycholinguists, such as Drozd (target article), would find C&T to be misguided with respect to these issues, because children's linguistic behaviour surely differs from adults' in seemingly unpredictable ways.

In this commentary I will take up the topic of the Crain & Thornton's (C&T) Modularity Matching Model vs. the approach C&T dub the Competing Factors Model, arguing that there is reason to adopt a model that includes elements of both those approaches, as I understand them.

Drodz in his review of Crain & Thornton's Investigations in Universal Grammar (IUG) raises a number of important issues which, I think, deserve further discussion. In what follows I will concentrate on two aspects that might be the source of children's non-adultlike linguistic behaviour, namely memory and methodological weaknesses in experimental work. I will briefly comment on the use of statistics.

Drozd's critique of Crain & Thornton's (C&T) (1998) book Investigations in Universal Grammar (IUG) raises many issues concerning theory and experimental design within generative approaches to language acquisition. I focus here on one of the strongest theoretical claims of the Modularity Matching Model (MMM): continuity of processing. For reasons different to Drozd, I argue that the assumption is tenuous. Furthermore, I argue that the focus of the MMM and the methodological prescriptions contained in IUG are too narrow to capture language acquisition.

C&T deserve credit for their concern for attaining empirical evidence, in particular evidence from language acquisition, for linguistic theory. They also deserve credit for bringing to the attention of the linguistic community the fact that variations in methodology do indeed produce variations in child behaviours, a fact well appreciated in behavioural sciences such as psychology, but often not fully appreciated outside of it; in particular, not in linguistics, a field which is fundamentally and rightfully ambivalent about its standing as a behavioural science, considering its relation to mathematics and formal theory as well as to sociolinguistics (Lust, Flynn, Foley & Chien, 1999). C&T also deserve credit for their appreciation of the importance of what children do NOT do (constraints) in language, and attempts to empirically verify such.

Our commentary concerns the Competing Factors Model (CFM). As Drozd says, the CFM is fictitious and without proponents. (See also McDaniel, 2001.) But we will argue that something like it is necessary to our field. Everyone recognizes multiple influences on language performance, even C&T. Most important, recognizing these factors does not require a denial of the grammar's existence or even of its dominance.

Drozd notes that Crain & Thornton's view of children's processing capacities (namely that they are the same as those of adults) is inconsistent both with the more widely held view that there are at least quantitative differences between the performance systems of children and adults, and with what is known about the acquisition of many grammatical phenomena. There is, I believe, an additional consideration that must be brought to bear here: there are highly suggestive parallels among children acquiring their first language, adults acquiring a second language, and Broca's (agrammatic) aphasics with respect to the comprehension of patterns that involve comparatively heavy demands on the processor. These parallels not only seem to confirm that children's processing resources are initially compromised, they point to the possibility of a greater role for processing in understanding grammatical development.

Complementing Bart Geurts' (2000) review of the same book, Ken Drozd's Learnability and linguistic performance points out several serious problems with the L1 acquisition research programme of Crain & Thornton (1998). Drozd's objections are so clearly stated that there is little I can add. Nonetheless, I will attempt to flesh out some of his more general points by examining more closely a specific case, namely the experiments in Crain, Thornton, Boster, Conway, Lillo-Martin & Woodams (1996) which focused on normal preschool children's understanding of simple universally quantified sentences.

Much of Drozd's penetrating review of Investigations in Universal Grammar (IUG), beyond noting countless lamentable misattributions of ideas and inconsistencies, evaluates its methodology. The standardization of methodology in IUG can, I believe, undermine our understanding of acquisition more than it supports it. It is a pity if we lose the real value of their useful experimental refinements of existing experiments (and several novel ones in semantics).