Children up to school age have been reported to perform poorly when interpreting sentences containing restrictive and additive focus particles by treating sentences with a focus particle in the same way as sentences without it. Careful comparisons between results of previous studies indicate that this phenomenon is less pronounced for restrictive than for additive particles. We argue that this asymmetry is an effect of the presuppositional status of the proposition triggered by the additive particle. We tested this in two experiments with German-learning three- and four-year-olds using a method that made the exploitation of the information provided by the particles highly relevant for completing the task. Three-year-olds already performed remarkably well with sentences both with auch ‘also’ and with nur ‘only’. Thus, children can consider the presuppositional contribution of the additive particle in their sentence interpretation and can exploit the restrictive particle as a marker of exhaustivity.

Comprehension of event order was compared for reversible ‘X because Y’ (‘Y because X’ is also logical) and non-reversible ‘X because Y’ sentences. Children aged 5; 8–10; 11 chose one of two picture sequences, differing in event order, and put two pictures in first/last order to match a sentence ‘X because Y’ (order of mention violates temporal order) or ‘Because Y, X’ (order of mention preserves temporal order). Reversibility and clause order effects reflected the use of semantic probability cues and order-of-mention strategies for comprehension. Judgements were also made of grammatical acceptability for correct and reversed ‘X because Y’ sentences. Response strategies used in the two experiments suggest that development of comprehension of the role of because reflects acquired independence from contextual support and acquisition of a meaning component: ORDER.

The relative importance of appearance and potential function in children's object naming was examined. Potential function is an object capability that may not be currently realized (e.g. an empty mug has the potential to hold coffee). In Study 1, sixteen children from each of three age groups (3;8, 4;8, and 6;1) were taught novel names for unfamiliar objects; they then had to decide whether these applied to items that resembled the training objects in either appearance or potential function. The youngsters were also shown deceptive objects (e.g., an eraser that looked like a pencil) and had to choose between familiar appearance and function names for them (e.g., pencil or eraser). The frequency of function-based responding in both tasks increased with age. In Study 2, the name training procedure was revised so that equal emphasis was given to both apparent and functional features. The main results of the first study were replicated. Neither study obtained evidence of a strong relation between the appearance—function shift and increased under-standing of the appearance—reality distinction.

The role of a strategy of reduplication in phonological acquisition and behaviour was examined in terms of: (1) the relationship between adoption of this strategy and children's failure to produce nonreduplicated multisyllabic forms and final consonants when attempting corresponding adult models; and (2) the role of the process of reduplication in production constraints. Comparisons of the phonologies of six children (1; 3–1; 9) classified as reduplicators and six children (1; 5–2; 0) classified as non-reduplicators revealed that the adoption/nonadoption of this strategy was closely related to the extent of production of nonreduplicated multisyllabic forms. Analyses of attempted words produced as reduplications revealed that this process served primarily to constrain multisyllabic productions. To a lesser degree, reduplication appeared to serve in conspiracies to constrain final consonant production.

We applaud Stoel-Gammon's (this issue) call for a more comprehensive account of the relationship between lexicon and phonology, and we strongly endorse her suggestions for future research. However, we think that it will not be enough simply to integrate findings and methods from the adult-centered and child-centered literatures. Both of these literatures suggest that we need to rethink standard assumptions about what phonological representations are and how they emerge to support the very large vocabularies that speakers develop over the course of a lifetime. Our commentary focuses on three themes relevant to this reconceptualization.

Monolingual infants are typically studied as a homogenous group and compared to bilingual infants. This study looks further into two subgroups of monolingual infants, monodialectal and multidialectal, to identify the effects of dialect-related variation on the phonological representation of words. Using an Intermodal Preferential Looking task, the detection of mispronunciations in familiar words was compared in infants aged 1;8 exposed to consistent (monodialectal) or variable (multidialectal) pronunciations of words in their daily input. Only monodialectal infants detected the mispronunciations whereas multidialectal infants looked longer at the target following naming whether the label was correctly produced or not. This suggests that variable phonological input in the form of dialect variation impacts the degree of specificity of lexical representations in early infancy.

Social deficits have been implicated in the language delays and deficits of children with autism (ASD); thus, the extent to which these children use language input in social contexts similarly to typically developing (TD) children is unknown. The current study investigated how caregiver input influenced the development of wh-question comprehension in TD children and language-matched preschoolers with ASD. Children were visited at four-month intervals over 1.5 years; mother–child play sessions at visits 1–2 were coded for maternal wh-question use. At visits 3–5 children watched videos in the Intermodal Preferential Looking paradigm, to assess their comprehension of subject and object wh-questions. Mothers' use of wh-questions with verbs and complex wh-questions positively predicted wh-question comprehension in the TD group; in contrast, mothers' use of wh-questions with ‘be’ as the main verb negatively predicted wh-question comprehension in the ASD group. Thus, TD children and children with ASD appear to use their linguistic input differently.

We report a syntactic priming experiment that examined whether children's acquisition of the passive is a staged process, with acquisition of constituent structure preceding acquisition of thematic role mappings. Six-year-olds and nine-year-olds described transitive actions after hearing active and passive prime descriptions involving the same or different thematic roles. Both groups showed a strong tendency to reuse in their own description the syntactic structure they had just heard, including well-formed passives after passive primes, irrespective of whether thematic roles were repeated between prime and target. However, following passive primes, six-year-olds but not nine-year-olds also produced reversed passives, with well-formed constituent structure but incorrect thematic role mappings. These results suggest that by six, children have mastered the constituent structure of the passive; however, they have not yet mastered the non-canonical thematic role mapping. By nine, children have mastered both the syntactic and thematic dimensions of this structure.

This paper presents a longitudinal study on the acquisition of first, second, and third person pronouns in twelve French-speaking and twelve English-speaking children. Comprehension and production data were collected every two months, beginning when the subjects were aged 1;6 and ending once pronouns were fully acquired. Three hypotheses concerning the rules children develop in learning pronouns were tested: (1) the person-role hypothesis (Charney, 1980), (2) the speech-role hypothesis (Clark, 1978), and (3) the name hypothesis (Clark, 1978). An analysis of children's pronominal confusion when they were addressed listeners as well as when they were non-addressed listeners was performed. The results indicated that the mastery of pronouns did not follow the developmental sequence predicted by the speech-role hypothesis; they provided evidence for the person-role hypothesis only when children were speakers, and partially supported the name hypothesis. The data also suggested that pronominal confusion is not a rare phenomenon among children tested in a non-addressee context. Finally, effects of child gender and native language were observed. Possible interpretations of the data are discussed.

We tested four predictions based on the assumption that optional infinitives can be attributed to properties of the input whereby children inappropriately extract non-finite subject–verb sequences (e.g. the girl run) from larger input utterances (e.g. Does the girl run? Let's watch the girl run). Thirty children with specific language impairment (SLI) and thirty typically developing children heard novel and familiar verbs that appeared exclusively either in utterances containing non-finite subject–verb sequences or in simple sentences with the verb inflected for third person singular -s. Subsequent testing showed strong input effects, especially for the SLI group. The results provide support for input-based factors as significant contributors not only to the optional infinitive period in typical development, but also to the especially protracted optional infinitive period seen in SLI.

Children's assignment of novel words to nameless objects, over objects whose names they know (mutual exclusivity; ME) has been described as a driving force for vocabulary acquisition. Despite their ability to use ME to fast-map words (Preissler & Carey, 2005), children with autism show impaired language acquisition. We aimed to address this puzzle by building on studies showing that correct referent selection using ME does not lead to word learning unless ostensive feedback is provided on the child's object choice (Horst & Samuelson, 2008). We found that although toddlers aged 2;0 at risk for autism can use ME to choose the correct referent of a word, they do not benefit from feedback for long-term retention of the word–object mapping. Further, their difficulty using feedback is associated with their smaller receptive vocabularies. We propose that difficulties learning from social feedback, not lexical principles, limits vocabulary building during development in children at risk for autism.

Thirty-six three- to four-year-old children were tested to assess whether hearing a word-referent link from an ignorant speaker affected children's abilities to subsequently link the same word with an alternative referent offered by another speaker. In the principal experimental conditions, children first heard either an ignorant or a knowledgeable speaker link a novel word with one of three toys. The first speaker's labelling episode was followed by a second in which a different speaker used the same novel label but for a different toy. There was also a Base-line condition which was the same as the experimental condition involving the ignorant speaker except that she did not associate the novel label with a referent. When tested for comprehension of the novel label, children selected the FIRST speaker's toy at high levels when the first speaker was knowledgeable, but selected the SECOND speaker's toy when the first speaker was ignorant. These findings suggest that children's experience with the ignorant speaker did not affect their abilities to learn a subsequently presented alternative word-referent link. These findings are discussed in terms of understanding the mechanisms by which children adapt their word-learning in line with speakers' knowledge states.

Temporal correspondences between the attainment of specific milestones in play and language were examined through a longitudinal study of four Japanese children (aged 0;7 to 0;11 at the beginning of the study). There were developmental correspondences between the onset of six language landmarks (the emergence of first words, naming words, vocabulary spurts, word-chains, nonproductive two-word utterances, productive two-word utterances) and the onset of subcategories of play. Language and play both reflected the development of underlying symbolic ability, and both developed in a parallel manner at the single-word stage. After the emergence of word-chains, language and play developed interdependently. All the children proceeded through the same sequence of stages, but the rate of development was different depending on their environment.

These are the principal questions of this study: are the early fonctions of negation, such as REJECTION, and the later emerging DENIAL no developmentally related? And when do children start to deny? So far, evidence for the questions at hand has been almost exclusively observational. We decided on a simple elicitation procedure instead, asking 48 children (ages between 1;1 and 2;7) easy yes/no-questions. The most likely age range for the appearance of denial no was 1;8–2;1. Its error-free acquisition supports the continuity theory of negation development, which holds that essentials of denial no carry over from the earlier fonctions of no. Finally an attempt is made to account for the beginnings of denial in terms of semantics and the representational theory of child cognition.

This study examined the vocabulary development of Norwegian second language (L2) learners with Urdu/Punjabi as their first language (L1) at two time-points from kindergarten to primary school, and compared it to the vocabulary development of monolingual Norwegian children. Using path models, the associations between number of picture books in the home, maternal education, and previous L1 and L2 vocabulary on the development of L2 vocabulary breadth and depth were investigated. The results indicate that despite the weaker vocabulary skills of the L2 sample, the growth trajectories of the L2 learners and the monolingual comparison group did not differ. For the L2 learners, we identified both concurrent and longitudinal predictors of vocabulary: the number of books in the home and the time of introduction of the L2 predicted concurrent vocabulary. L1 vocabulary, number of books in the home, and the time of introduction of the L2 predicted vocabulary growth.

The use of Italian morphology was examined in 34 children ranging in age from 2;6 to 5;0. By the age of 3;6–4;0, high percentages of use in obligatory contexts were seen for a number of grammatical morphemes. Children age 2;6–3;0 showed percentages of use that were somewhat lower than those seen for the older children. In this age range, singular forms were used with higher percentages in obligatory contexts than plural forms, for several different types of grammatical morphemes. Greater control over singular forms in these younger children was corroborated by data from a comprehension task. Even at the younger ages studied, use of grammatical morphemes did not seem influenced by whether phonological eues to agreement were present, or whether the grammatical morphemes were homonymous. Percentages for grammatical morphemes in the form of free-standing morphemes were somewhat lower than percentages for morphemes taking the form of inflections, suggesting that the obligatory nature of inflections in Italian may be a more influential factor than the amount of morphological information contained in a grammatical morpheme.

Time is frequently expressed with spatial motion, using one of three different metaphor types: moving-time, moving-ego, and sequence-as-position. Previous work shows that children can understand and explain moving-time metaphors by age five (Özçalışkan, 2005). In this study, we focus on all three metaphor types for time, and ask whether metaphor type has an effect on children's metaphor comprehension and explanation abilities. Analysis of the responses of three- to six-year-old children and adults showed that comprehension and explanation of all three metaphor types emerge at an early age. Moreover, children's metaphor comprehension and explanation vary by metaphor type: children perform better in understanding and explaining metaphors that structure time in relation to the observer of time (moving-ego, moving-time) than metaphors that structure time without any relation to the observer of time (sequence-as-position-on-a-path). Our findings suggest that children's bodily experiences might play a role in their developing understanding of the abstract concept of time.

Previous studies have reported systematic individual differences among children in their noun and pronoun use. This study examined mothers' use of nouns and pronouns and their references to objects and persons as environmental variables which might relate to children's nominal preferences. Mothers' speech to children classified as referential or expressive in speech style (Nelson 1973) at low and high MLU levels (Nelson 1975) was analysed, and differences relating to children's style and MLU were reported. Results showed no relationship between mothers' use of nouns or pronouns and children's speech style, but did show that mothers' references to objects and persons were related to children's style. These findings are the strongest evidence to date that environmental factors contribute to stylistic differences in language acquisition, and also give support to Nelson's (1973) hypothesis that the communicative functions of language are an important factor in referential and expressive speech styles.

Recent years have witnessed a cognitivist reaction against previous views of language learning. It had been held that mere exposure to language is a sufficient condition for language acquisition, whether by hypothesis testing (Katz 1966) or through passive learning (Braine 1971). Symptomatic of this approach were experiments investigating the learning of grammar in which subjects were taught artificial miniature languages without meaning, either through making guesses and receiving feedback from the experimenter (e.g. Hunt 1965) or passively, just by listening (Braine 1971). Although no such claim was explicitly made, language learning was actually treated as if it occurred independently of cognitive development. This one-sided approach has since been corrected by the cognitivists as represented in particular by the Geneva school (Sinclair 1971), who stress the importance of general cognitive development in language acquisition. Experiments with artificial languages bear the imprint of this approach and now involve semantic referents of the linguistic symbols (e.g. Moeser & Bregman 1972, 1973).