Why are young children's utterances short? This elicited imitation study used a new task – double imitation – to investigate the factors that contribute to children's failure to lexicalize sentence subjects. Two-year-olds heard a triad of sentences singly and attempted to imitate each; they then again heard the same triad singly and again attempted to imitate each. Comparisons between the two attempts showed that children's second passes were more accurate than their first. In addition, independent of sentence length, children increased their inclusion of pronominal and expletive but not lexical subjects. Children included verbs more often from sentences with pronominal than lexical subjects, suggesting a trade-off. Children included subjects more often in short sentences than long ones, and increased subject inclusion only in short sentences. The results suggest that children's language production is similar to adults': a complex interaction of syntactic knowledge, limited cognitive resources, communicative goals, and conversational structure.

The spelling of words in English is governed in part by the morphemes that make them up. This study examines the strength of children's knowledge of the role of root morphemes in spelling, specifically focusing on whether it can withstand interference by phonological changes. A total of 75 children between seven and nine years of age were given the first parts of two-morpheme transparent and opaque derived words (e.g. musical and objection) and one-morpheme control words (e.g. metal and portion). Children used the clues to a significant extent with the two-, but not the one-morpheme words. This effect was consistent across age groups and across both types of derived words. This is evidence that children's understanding of the link between morphemes and spelling is not impeded by changes in the sound of morphemes. These findings have substantial implications for models of spelling development and for educational practice.

The family size of the constituents of compound words, or the number of compounds sharing the constituents, has been shown to affect adults' access to compound words in the mental lexicon. The present study was designed to see if family size would affect children's segmentation of compounds. Twenty-five English-speaking children between 3;7 and 5;9 were asked to explain the meaning of existing compounds with constituents of varying family size to an alien puppet. The results showed that children were more likely to mention the modifier of compounds if they came from large constituent families than if they came from small constituent families. Other variables were also shown to have some, but smaller effects on children's parsing, including the frequency of the constituent words and the compounds, whether the compounds were already known, and age. These results suggest that children's segmentation of compounds might be facilitated by analogy with other compounds already in their vocabularies.

The goal of this research is to determine the relevant factors that aid in the acquisition of the perfective aspect in Russian. Results confirm the findings of previous research, which say that aspect is not learned as a uniform category, but rather interrelates with the acquisition of Aktionsarten. This study focuses on the factors responsible for the difference in the rate of the acquisition of two complementary Aktionsarten in the perfective aspect: telic verbs (verbs including a result/goal of the denoted event) and ingressive verbs (verbs including the beginning of the event).

Since the usage of Aktionsarten strongly depends on the surrounding discourse, two experiments that varied in their discourse complexity were conducted. One study looked at the production of isolated utterances (thirty-nine children aged 3;0 to 6;11) and the other study focused on complex texts (fifty-two children aged 3;0 to 6;11). It was found that while telics are used independently of discourse context, ingressives depend strongly on contextual information.

These results suggest that discourse complexity and narrative competence define the acquisitional process for ingressives, yet are irrelevant in the acquisition of telics.

The specificity of infants' phonological representations is examined by comparing their sensitivity to mispronunciations of novel and familiar words, using the preferential looking task. 29 children at 1;2 were trained and tested on familiar and novel word–object pairs. Children showed evidence of sensitivity to mispronunciations of novel and familiar words, indicating detailed phonological representations. Discrepancies between this study and earlier investigations are discussed with reference to differences between habituation and preferential looking tasks.

This study compares homonym learning to novel word learning by three- to four-year-old children to determine whether homonyms are learned more rapidly or more slowly than novel words. In addition, the role of form characteristics in homonym learning is examined by manipulating phonotactic probability and word frequency. Thirty-two children were exposed to homonyms and novel words in a story with visual support and learning was measured in two tasks: referent identification; picture naming. Results showed that responses to homonyms were as accurate as responses to novel words in the referent identification task. In contrast, responses to homonyms were more accurate than responses to novel words in the picture-naming task. Furthermore, homonyms composed of common sound sequences were named more accurately than those composed of rare sound sequences. The influence of word frequency was less straightforward. These results may be inconsistent with a one-to-one form–referent bias in word learning.

In this note we discuss pMLU, a whole-word measure for phonological development that was proposed by Ingram (2002). Ingram's rules for calculating pMLU are analysed and we point at the crucial role of the level of transcription for making pMLU measurements comparable over different corpora. The main aim of the paper is an assessment of the reliability and the validity of pMLU. The assessment is accomplished using a computational tool for measuring pMLU on two large Dutch CHILDES corpora. We propose minimal sample sizes for reliable measurements relative to the stage of phonological development.

Effects of negative input for 13 categories of grammatical error were assessed in a longitudinal study of naturalistic adult–child discourse. Two-hour samples of conversational interaction were obtained at two points in time, separated by a lag of 12 weeks, for 12 children (mean age 2;0 at the start). The data were interpreted within the framework offered by Saxton's (1997, 2000) contrast theory of negative input. Corrective input was associated with subsequent improvements in the grammaticality of child speech for three of the target structures. No effects were found for two forms of positive input: non-contingent models, where the adult produces target structures in non-error-contingent contexts; and contingent models, where grammatical forms follow grammatical child usages. The findings lend support to the view that, in some cases at least, the structure of adult–child discourse yields information on the bounds of grammaticality for the language-learning child.

It is well-established that (non-linguistic) categorization is driven by a functional demand of prediction. We suggest that prediction likewise may well play a role in motivating the learning of semantic generalizations about argument structure constructions. We report corpora statistics that indicate that the argument frame or construction has roughly equivalent cue validity as a predictor of overall sentence meaning as the morphological form of the verb, and has greater category validity. That is, the construction is at least as reliable and more available than the verb. Moreover, given the fact that many verbs have quite low cue validity in isolation, attention to the contribution of the construction is essential.

This article explores whether infants are able to learn words as rapidly as has been reported for preschoolers. Sixty-four infants aged 1;6 were taught labels for either two moving images or two still images. Each image–label pair was presented three times, after which comprehension was assessed using an adaptation of the intermodal preferential looking paradigm. Three repetitions of each label were found to be sufficient for learning to occur, fewer than has previously been reported for infants under two years. Moreover, contrary to a previous finding, learning was equally rapid for infants who were taught labels for moving versus still images. The findings indicate that infants in the early stages of acquiring a vocabulary learn new word-referent associations with ease, and that the learning conditions that allow such learning are less restricted that was previously believed.

This paper reports on an investigation of children's (aged 3;5–9;8) comprehension of sentences containing ambiguity of prepositional phrase (PP) attachment. Results from a picture selection study (N=90) showed that children use verb semantics and preposition type to resolve the ambiguity, with older children also showing sensitivity to the definiteness of the object NP as a cue to interpretation. Study 2 investigated three- and five-year-old children's (N=47) ability to override an instrumental interpretation of ambiguous PPs in order to process attributes of the referential scene. The results showed that while five-year-olds are capable of incorporating aspects of the referential scene into their interpretations, three-year-olds are not as successful. Overall, the results suggest that children are attuned very early to the lexico-semantic co-occurrences that have been shown to aid ambiguity resolution in adults, but that more diffuse cues to interpretation are used only later in development.

This study focuses on parent–child book reading and its connection to the development of a theory of mind. First, parents were asked to report about frequency of parent–child storybook reading at home. Second, mothers were asked to read four picture-books to thirty-four children between 4;0 and 5;0. Both frequency of parent–child storybook reading at home, and mother's use of mental state terms in picture-books reading tasks were significantly associated with success on false belief tasks, after partialling out a number of potential mediators such as age of children, verbal IQ, paternal education, and words used by mothers in joint picture-book reading. Among the different mental state references (cognitive terms, desires, emotions and perceptions), it was found that the frequency and variety of cognitive terms, but also the frequency of emotional terms correlated positively with children's false belief performance. Relationships between mental state language and theory of mind are discussed.

The present study investigates whether five-to-six-year-old children with Williams syndrome (N=8) can form new object categories based on naming information alone, and compares them with five groups of typically developing children aged 2;0 to 6;0 (N=34 children). Children were presented with triads of dissimilar objects; all objects in a triad were labelled, two of them with the same pseudoname. Name-based categorization was evaluated through object selection. Performance was above chance level for all groups. Performance reached a ceiling at about 4;0 for the typically developing children. For the children with Williams Syndrome, performance remained below chronological age level. The present results are discussed in light of previous findings of a failure to perform name-based categorization in younger children with Williams syndrome and the persistent asynchrony between cognitive and lexical development in this disorder.

This study charts the development of the genitive masculine inflection, one of the most irregular parts of the Polish case-marking system. 72 Polish children aged from 2;3 to 10;8 participated in a nonce word production experiment testing their ability to supply the genitive form and their sensitivity to the semantic factors determining the choice of ending. Results indicate that productivity, or the ability to supply the inflected form of some nonce words, emerges early: 78% of the two-year-olds were able to inflect at least one test item. However, mastery, or the ability to consistently supply the correct ending, takes considerably longer to develop, and adultlike levels of provision are not reached until about age 10;0.

Two studies investigating young readers' use of conjunctions are reported. In Study One, 145 eight- to ten-year-olds completed one of two narrative cloze tasks in which different types of conjunction were deleted. Performance for additive conjunctions was not affected by age in this study, but older children were more likely to select the target conjunction than were younger children for temporal, causal, and adversative terms. Performance was superior in the cloze task in which they were given a restricted choice of responses (three vs. seven). In Study Two, 35 eight- and nine-year-old good and poor comprehenders completed the three-choice cloze task. The poor comprehenders were less likely to select the target terms in general. Sentence-level comprehension skills did not account for their poor performance. The results indicate that understanding of the semantic relations expressed by conjunctions is still developing long after these terms are used correctly in children's speech. The findings are discussed in relation to the role of conjunctions in text comprehension.

This paper describes the acquisition of the 3rd person pronoun ‘il/elle’ (he, she, it) in seven to twelve-year-old French children (N=58), in written production. An experiment was conducted to examine the relationship between the use of this anaphoric pronoun and the accessibility of the memory-trace of the corresponding referent in the texts. Referential accessibility in short texts was varied according to three factors: referential distance, thematization of the agent role (first sentence subject), and discourse focus. We found that the children were sensitive to the distance factor as early as 7;0, i.e. they used fewer personal pronouns when the referential distance increased. However, children of different ages differed in their weighting of the discourse focus factor and the thematization factor: the seven-year-olds (N=18) and the eleven-year-olds (N=20) were sensitive to variation of the discourse focus but not the thematization factor, while for the nine-year-olds (N=20) it was the reverse. The main results suggest: (a) when seven and nine-year-olds use the pronoun ‘il/elle’, they do not comply with the constraints associated with the accessibility of the memory-trace of the referent; (b) memory constraints have an effect from the age of 7;0, but only when the discourse focus is maintained. It was concluded that the discourse management of the French personal pronoun ‘il/elle’ is not totally mastered at 11;0: children cannot operationally integrate the whole array of constraints implied in anaphoric management.

We investigated whether manipulating the perceived novelty of nameless objects would influence two-year-olds' tendency to map novel words to these objects. In Experiment 1, children who had been pre-exposed to target nameless objects were more likely to map novel words onto those objects than children who were not pre-exposed to the objects or children who were pre-exposed to non-target members of the nameless object categories. In Experiment 2, children who were pre-exposed to a nameless object were more likely to assign the novel label to that object than to either a familiar object or an unfamiliar object that had not been pre-exposed. The results of these studies suggest that reducing the novelty of nameless objects increases two-year-olds' tendency to map a novel word to a nameless object.

This study investigates subject omission in six English-Inuktitut simultaneous bilingual children, aged 1;8–3;9, to examine whether there are cross-language influences in their language development. Previous research with other language pairs has shown that the morphosyntax of one language can influence the development of morphosyntax in the other language. Most of this research has focused on Romance-Germanic language combinations using case studies. In this study, we examined a language pair (English-Inuktitut) with radically different morphosyntactic structures. Analysis of the English-only and Inuktitut-only utterances of the children revealed monolingual-like acquisition patterns and subject omission rates. The data indicate that these bilingual children possessed knowledge of the target languages that was language-specific and that previously identified triggers for crosslinguistic influence do not operate universally.