The ability to make clear reference in connected discourse was examined in children learning Cantonese, a Chinese language where noun phrase constituents, whatever their grammatical role, are omissible from sentences under discourse conditions that are not well-understood. Forty-three typically developing children aged 3;0, 5;0, 7;0 and 12;0 told 16 stories based on picture sequences. A panel of adult native Cantonese speakers was asked to judge the referential adequacy of each child's stories by identifying the character the child was talking about in 32 targeted referential acts. The targeted acts were of three sorts: MAINTENANCE of a known character, INTRODUCTION of a second new character, and REINTRODUCTION of a known character. Reference was judged to be adequate when 3 out of 4 ‘listeners’ could successfully identify the character. Children's referential expressions were most adequate for Maintenance, less adequate for Introduction, and least adequate for Reintroduction. The twelve- and seven-year-olds approached ceiling on all three functions. The five-year-olds scored poorly on Reintroduction, and the three-year-olds failed both Introduction and Reintroduction, despite knowledge of at least one of the possible linguistic forms required for these acts as evidenced in a sentence imitation task. Viewed within the framework of Levelt's (1989) discourse model, the data improve our understanding of the developmental period during which children learn to make appropriate presuppositions about the listener's knowledge and attentional states.

Interactions between six toddlers (aged 1;0 to 1;6) and adults were examined to ascertain adult perceptions of toddler utterance relatedness and to determine temporal and interactional features that underlie those perceptions. Five raters made judgments regarding relatedness of the child utterances to the previous adult utterances; 251 utterances were examined. Utterances judged by adults as related occurred within 4·25 seconds of the preceding adult utterance nearly 90% of the time. This study also points to the need for using interactional categories that go beyond describing utterance relatedness, and introduces terms (i.e. co-participatory, initiation, narrowed focus) for doing so.

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.

In two eye-tracking experiments, we investigate adults' and children's on-line processing of referentially ambiguous English pronouns. Sixteen adults and 16 four-to-seven-year-olds listened to sentences with either an unambiguous reflexive (himself) or an ambiguous pronoun (him) and chose a picture with two characters that corresponded to those in the sentence. For adults, behavioural data, responses and reaction times indicate that pronouns are referentially ambiguous. Adults' eye movements show a competition between the looks to sentence-internal and -external referents for pronouns, but not for reflexives. Children overwhelmingly prefer the sentence-internal referent in the off-line picture selection task. However, their eye movements reveal implicit awareness of referential ambiguity that develops earlier than their explicit knowledge in the picture selection task. This discrepancy between performance on a looking measure and a pointing measure in the children's processing system is explained by a general dissociation between implicit and explicit knowledge proposed in recent literature on cognitive development.

Comprehension of relative clauses was assessed in 10 Hebrew-speaking school-age children with syntactic SLI and in two groups of younger children with normal language development. Comprehension of subject- and object-relatives was assessed using a binary sentence-picture matching task. The findings were that while Hebrew-speaking children with normal development comprehend right-branching object relatives around the age of 6;0, children with syntactic SLI are still at chance level in object relatives by age 11;0. The four-year-olds were also at chance on object relatives. Comprehension of subject relatives was good in the SLI group, similar to the six-year-olds, and significantly better than the four-year-olds. The syntactic impairment is interpreted as a selective deficit to non-canonical sentences that are derived by movement.

We explored vocabulary competence in 55 firstborn and secondborn sibling pairs when each child reached 1;8 using multiple measures of maternal report, child speech, and experimenter assessment. Measures from each of the three sources were interrelated. Firstborns' vocabulary competence exceeded secondborns' only in maternal reports, not in child speech or in experimenter assessments. Firstborn girls outperformed boys on all vocabulary competence measures, and secondborn girls outperformed boys on most measures. Vocabulary competence was independent of the gender composition and, generally, of the age difference in sibling pairs. Vocabulary competence in firstborns and secondborns was only weakly related.

The effect of both geometric and extra-geometric factors on children's production of in is reported (free-response paradigm). Eighty children across four age groups (means 4;1, 5;5, 6;1, and 7;1) were shown video scenes of puppets placing real objects in various positions with reference to a bowl and a plate. Located objects were placed at three heights on top of piles of other objects in the scene. The extra-geometric factor of location control of the located object was manipulated by comparing static scenes to dynamic scenes in which the located object was depicted as either moving independently of, or together with, the reference object. Additionally, the located object was placed on other objects that were either the same or different (e.g. an apple on apples or on oranges). The results indicate that even the youngest children altered the way they talked according to not only geometric but also extra-geometric factors.

This study examines the production of regular and irregular participle forms of German with high and low frequencies using a speeded production task. 40 children in two age groups (five- to seven-year olds, eleven- to twelve-year olds) and 35 adult native speakers of German listened to stem forms of verbs presented in a sentential context and were asked to produce corresponding participle forms as quickly and accurately as possible. Dependent variables were the subjects' participle-production latencies and error rates. We found contrasts between the production of regular and irregular forms in both children and adults, with respect to the production latencies and types of morphological error. Children overapplied the regular patterns to forms that are irregular in the adult language, but not vice versa. High-frequency irregular participles were produced faster (and amongst the children more accurately) than low-frequency ones, whereas regular participles yielded a reverse frequency effect, i.e. longer production latencies for high-frequency forms than for low-frequency ones, in the two groups of children as well as in one subgroup of adults. We explain these findings from the perspective of dual-mechanism models of inflection arguing that the mental mechanisms and representations for processing morphologically complex words (‘words’ and ‘rules’) are the same in children and adults, and that the observed child/adult differences in participle production are due to slower and less accurate lexical access in children than in adults.

Recent studies have suggested that cultures vary in subtle ways in the talk about talk that children hear and learn to produce. Twenty-two three-year-old children and their families in respectively Oslo, Norway and Cambridge, Massachusetts were observed during mealtime with the aim of identifying talk-focused talk. The analysis distinguished talk about (a) language per se, (b) discourse management, and (c) former conversations and use of reported speech. No category of talk-focused talk appeared exclusively in either community, and the frequency of such talk was similar across these. The Oslo families talked more often about language per se and their talk-focused conversations typically had a question–answer form. Talk about talk appeared more often within narratives in Oslo and within explanations in Cambridge. A second analysis compared talk-focused talk at home with such talk at school, suggesting that talk about language per se appeared more often at school across the two communities.

Many researchers believe that there is a logical problem at the centre of language acquisition theory. According to this analysis, the input to the learner is too inconsistent and incomplete to determine the acquisition of grammar. Moreover, when corrective feedback is provided, children tend to ignore it. As a result, language learning must rely on additional constraints from universal grammar. To solve this logical problem, theorists have proposed a series of constraints and parameterizations on the form of universal grammar. Plausible alternatives to these constraints include: conservatism, item-based learning, indirect negative evidence, competition, cue construction, and monitoring. Careful analysis of child language corpora has cast doubt on claims regarding the absence of positive exemplars. Using demonstrably available positive data, simple learning procedures can be formulated for each of the syntactic structures that have traditionally motivated invocation of the logical problem. Within the perspective of emergentist theory (MacWhinney, 2001), the operation of a set of mutually supportive processes is viewed as providing multiple buffering for developmental outcomes. However, the fact that some syntactic structures are more difficult to learn than others can be used to highlight areas of intense grammatical competition and processing load.

This study examined the on-line processing of French sentences in a grammaticality judgment experiment. Three age groups of French children (mean age: 6;8, 8;6 and 10;10 years) and a group of adults were asked to detect grammatical violations as quickly as possible. Three factors were studied: the violation type: agreement violations (number and gender) vs. word order violations; the violation position: early vs. late in the sentence; the target type of the violations: intra vs. interphrasal. An example of an early interphrasal verbal agreement violation follows: ‘Chaque semaine la voisine remplissent le frigo après avoir fait les courses au marché’ (Every week the neighbour fill the fridge after shopping at the market). The main developmental results were the following: not surprisingly, children were always slower than adults in the detection of grammatical violations. At each age level, morphological violations were more rapidly detected than word order violations. Each age group was faster at judging sentences with later occurring violations and the position effect was especially strong in the youngest groups. Finally, intraphrasal violations were more rapidly detected than interphrasal ones, this effect being observed only in the oldest groups (i.e. 10;10 years and adults). The results were compared to previous on-line data obtained in modern Greek (Kail & Diakogiorgi, 1998) showing strong similarities, even though Greek is a very rich morphological language. These results are discussed within the framework of the Competition Model, outlining the necessity to incorporate new processing constraints into the model.

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.

Mazzocco (1997) claimed that children have persistent difficulty in learning pseudo-homonyms – words like rope used to refer to a novel object (e.g. spade). Because the novel objects were familiar, the pseudo-homonyms in her study were also synonyms (i.e. rope and spade both now mean spade). The results could therefore be due to children's well-known difficulties in learning synonyms. In Experiment 1, 55 six- to ten-year-olds used story context to select referents for pseudo-homonyms from picture sets containing the intended referents, with primary referents amongst the distractors. Children were equally poor when the intended referents were familiar (e.g. spade) as when they were unfamiliar (e.g. tapir) – 35 and 38% correct, respectively. This indicates that familiarity of referent does not account for children's difficulties. In Experiment 2, 64 five- to ten-year-olds received instruction about homonymy, then a story set without pictures of the primary referents, in order to make the experimenter's intentions clear. Children were then shown one of the story sets from Experiment 1. Performance was just as poor (38% correct), indicating that misunderstanding of task demands did not account for failure. The conclusion is that Mazzocco's findings represent a psychologically interesting developmental difficulty.

This study aimed to clarify the development of conversational style in Japanese mother–child interactions. We focused on the frequency of speech overlap as an index of Japanese conversational style, with particular attention to ne, a particle produced by the speaker, and to backchannels, such as ‘uh-huh’, produced by the listener that support sympathetic conversation. The results of longitudinal observations of two Japanese mother–child dyads from approximately 0;11 to 3;3 suggest that an adultlike conversational style with frequent overlaps emerges in Japanese child-directed speech around the two-word utterance period, and a child's development of ne use is closely related to this shift.

MacWhinney's stimulating discussion suggests that there are many lines of argument that may address concerns raised by theorists who are concerned that there is a logical problem of language acquisition. This commentary argues: (1) that if the ‘logical problem’ applied to language, it would apply, with curious consequences to any learning by experience; (2) that the logical problem does not apply – given sufficient positive data from any reasonable language, language can be learned, in a probabilistic sense, by an ‘ideal learner’ using a simplicity principle; and (3) that a simplicity, or minimum description length, principle may provide a useful methodology for assessing claims concerning learnability of particular linguistic structures.

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.