Children aged 2;0 to 2;6 participated in a longitudinal study examining their acquisition of the English auxiliary system following a six-week period in which they were exposed to additional auxiliary input in varying sentence contexts. Groups of children received enrichment utterances with the auxiliary could either in first position in the sentence, in middle position, or in both positions. Children in the front position group were significantly advanced over the other experimental groups in acquiring modal auxiliaries but not non-modals. However, none of the experimental groups differed significantly from a baseline group which received no additional could input. The implications of these findings for understanding the mechanisms of auxiliary acquisition and the nature of children's grammatical categories are discussed.

The properties of reflexives vary across adult languages with respect to (i) the domain in which a reflexive may be bound and (ii) the syntactic positions an appropriate antecedent may occupy. These two issues have been approached in GB theory in various ways, each with specific implications for acquisition. In this paper we examine these implications by testing normal and Specific Language Impaired (SLI) children for evidence of the binding domain and orientation properties of their grammars. The investigation reveals that, contrary to most previous claims, normal children acquiring English pass through a long-distance binding stage. SLI children, however, do not display this pattern, tending instead to behave like very young normal children in requiring the nearest available NP to be the antecedent. We argue that this constitutes an early binding stage not previously identified. Finally, we interpret our findings in terms of a conception of acquisition dubbed the ‘competing grammars’ model, according to which competing incompatible grammars may coexist in the mind of the learner.

The development of forms and functions of negation in parent–child interactions in the early stages of language acquisition is discussed with illustrative examples from field data relating to two Tamil-speaking children and their parents. An attempt is made to provide a scheme for analysing the negatives in children's speech, maintaining the three basic functions of Bloom (1970) unaltered. Subcategories of these functions are introduced, taking into consideration the interactional situations as they are perceived by the parents and children. Children, it is observed, acquire the forms and functions of negation in a clear developmental sequence. They acquire and use the free forms naanaa (veeṇḍaam) ‘No, I don't want’ first, followed by negatives involving bound forms. Certain forms like maaṭṭeen ‘I won't’, muḍiyaadi' I can't’ and even veeṇḍaam are used in isolation (as free forms) first. Only later are they used with verb infinitives. The development of functions of negation follows the sequence: rejection, non-existence, prohibition and denial. Thus the children of this study show preference for rejection over non-existence as observed by earlier scholars.

This study investigates children's acquisition of the distinction between direct speech (Elephant said, “I get the football”) and indirect speech (Elephant said that he gets the football), by measuring children's interpretation of first, second, and third person pronouns. Based on evidence from various linguistic sources, we hypothesize that the direct–indirect distinction is acquired relatively late. We also predict more mistakes for third person pronouns compared to first and second person pronouns. We tested 136 Dutch-speaking children between four and twelve in a referent selection task and found that children interpret pronouns in direct speech predominantly as in indirect speech, supporting our hypothesis about a late acquisition of the direct–indirect distinction. In addition, we found differences between I, you, and he that deviate from a simple first and second vs. third person split. We discuss our results in the light of cross-linguistic findings of direct–indirect mixing.

Because of its structural characteristics, specifically the prevalence of verb types in infant-directed speech and frequent pronoun-dropping, the Italian language offers an attractive opportunity to investigate the predictive effects of input frequency and positional salience on children's acquisition of nouns and verbs. We examined this issue in a sample of twenty-six mother–child dyads whose spontaneous conversations were recorded, transcribed, and coded at 1;4 and 1;8. The percentages of nouns occurring in the final position of maternal utterances at 1;4 predicted children's production of noun types at 1;8. For verbs, children's growth rates were positively predicted by the percentages of input verbs occurring in utterance-initial position, but negatively predicted by the percentages of verbs located in the final position of maternal utterances at 1;4. These findings clearly illustrate that the effects of positional salience vary across lexical categories.

In this study, we investigated how Mandarin-speaking children and adults interpret focus structures like Zhiyou Yuehan chi-le pingguo ‘Only John ate an apple’ and Shi Yuehan chi-de pingguo ‘It is John who ate an apple’. We found that children tended to associate focus operators zhiyou ‘only’ and shi ‘be’ with the verb phrase (VP), whereas adults uniquely associated them with the subject noun phrase (NP). To account for this difference, we propose that children initially treat focus operators as adverbials, thus ending up associating them with the VP. In order to assess our proposal, we examined children's understanding of zhiyou-constructions with negation, like Zhiyou Yuehan meiyou chi pingguo ‘Only John didn't eat an apple’. It was found that children, like adults, consistently associated the focus operator with the subject NP in this construction. The findings have an important bearing on language learnability, since negation assists children in reaching the adult-like interpretation.

We tested 24 caregivers of preschool children to determine whether their strategies for teaching novel adjectives are consistent with children's demonstrated abilities to learn these words (e.g. Waxman & Klibanoff, 2000). On each of four trials, caregivers had to select one of two cards, both of which showed a familiar object bearing an unfamiliar property. On the within-basic card, the object was accompanied by a second object from the same basic-level category; on the across-basic card, this second object came from a different basic-level category. Caregivers' task was to choose the card that would be more helpful to teach a novel adjective for the unfamiliar property. If the second object differed from the first in terms of a novel target property, caregivers (N = 12) stated a strong preference for the within-basic card. If the two objects agreed in terms of the novel property, caregivers (N = 12) indicated a clear preference for the across-basic card. The findings offer new insight into the speed and efficiency of lexical development, by revealing that word teachers, like word learners (cf. Waxman & Klibanoff, 2000), are sensitive to the conditions under which certain contrasts (in property or in basic-level category) are effective in promoting the successful acquisition of novel adjectives.

Stoel-Gammon (this issue) highlights the close and symbiotic association that exists between the lexical and phonological domains in early linguistic development. Her comprehensive review considers two bodies of literature: (1) child-centred studies; and (2) studies based on adult psycholinguistic research. Within the child-centred studies, both prelinguistic and early meaningful speech is examined. Stoel-Gammon organizes her review of child-centred studies around a series of postulates that capture the associations between lexical and phonological development and here she focuses primarily on normally developing children acquiring American English. My intention is not to question these postulates, which are based on established research findings, but to extend them beyond the limits of her review. In my commentary, I would like to explore the application of some of the stated postulates of the early meaningful speech period in children acquiring two or more languages. In so doing, I add a cross-linguistic dimension to the discussion; a dimension that Stoel-Gammon would like to see pursued in future research on this topic. I also expand our understanding of lexical–phonological relationships by considering the potential for interaction in multiple lexical–phonological relationships.

Children categorize native-accented speakers as local and non-native-accented speakers as foreign, suggesting they use accent (i.e., phonological proficiency) to determine social group membership. However, it is unclear if accent is the strongest – and only – group marker children use to determine social group membership, or whether other aspects of language, such as syntax and semantics, are also important markers. To test this, five- to eight-year-old monolingual English-speaking children were asked to judge whether individuals who varied in phonological, syntactic, and semantic proficiency were local or foreign. Children were also asked which individual they wanted as a friend. Children prioritized phonological proficiency over syntactic and semantic proficiency to determine social group membership. However, with age, children begin to shift toward prioritizing syntactic and semantic proficiency over phonological proficiency in their friendship decisions, suggesting that the capacity to integrate different aspects of a speaker's linguistic proficiency changes with development.

This study compares parental pause and utterance duration in conversations with Swedish speaking children at age 1;6 who have either a large, typical, or small expressive vocabulary, as measured by the Swedish version of the McArthur-Bates CDI. The adjustments that parents do when they speak to children are similar across all three vocabulary groups; they use longer utterances than when speaking to adults, and respond faster to children than they do to other adults. However, overall pause duration varies with the vocabulary size of the children, and as a result durational aspects of the language environment to which the children are exposed differ between groups. Parents of children in the large vocabulary size group respond faster to child utterances than do parents of children in the typical vocabulary size group, who in turn respond faster to child utterances than do parents of children in the small vocabulary size group.

This study investigated the development of evaluation in narratives from middle to late childhood, within the context of differentiating between spoken and written modalities. Two parallel forms of a picture story were used to elicit spoken and written narratives from fourth- and sixth-graders. It was expected that, in addition to an increase of evaluative devices with age, written narratives would exhibit a higher frequency and diversity as a result of the intrinsic differences between the two modalities. From a developmental perspective, the results showed that only few categories exhibited the expected increase with age. Qualitative analyses provided a fruitful method to illustrate developmental changes. The results further indicated that modality had the expected impact on the diversity, and on the frequency, of most categories of evaluative language. Specifically, markers of decontextualized language and categories with a high degree of syntactic complexity were prone to modality differences.

The present article focused on two types of communicative intent (directing behaviour vs. eliciting talk) expressed by mothers and teenagers during everyday family interactions in Estonian, Finnish, and Swedish mono- and bicultural families. Three monocultural groups consisted of 17 Estonian, 19 Swedish, and 18 Finnish families living in their country of origin; two bicultural and bilingual groups consisted of 18 Estonian and 18 Finnish families residing in Sweden. All the children were between 9;0 and 13;0. The results revealed that the Estonian monocultural mothers were highly directive and direct: issuing behavioural directives most frequently and using the highest proportion of imperatives among all samples. Contrary to our expectations, the mothers who tended to be more concerned with controlling their children's behaviour also elicited conversation more frequently from teenagers by using a larger number of information requests. These requests seemed to serve as another form of attempted control over adolescents' behaviour – their communicative behaviour. The Swedish monocultural children were more active in controlling their mothers' behaviour than their counterparts, possibly illustrating the Swedish value of generational equality.

Children undergo gradual progression in their ability to differentiate correct and incorrect pronunciations of words, a process that is crucial to establishing a native vocabulary. For the most part, the development of mature phonological representations has been researched by investigating children's sensitivity to consonant and vowel variation, with a much lesser focus on lexical tones. The current study investigates sensitivity to lexical tones in word recognition with specific attention to role of perceptual salience. Chinese-speaking preschoolers were presented with familiar words that were correctly pronounced, substituted for a subtle tone variant (Tones 2 and 3), or substituted for a salient tone variant (Tones 1 and 4). Results demonstrated that subtle tone variants were mistakenly perceived as correct pronunciations and only salient tone variants were recognized as mispronunciations. Findings suggest that tone integration follows a more complex developmental course that previously concluded.

Two recent papers (de Villiers & Johnson, 2007; Johnson, de Villiers & Seymour, 2005) have claimed that children have difficulty with verbal -s until five–six-years-old. This contrasts with perceptual studies showing evidence for sensitivity to the grammatical properties of verbal -s as young as 1; 4. These apparently conflicting findings can be reconciled by differentiating between early perceptual grammatical knowledge and later semantic comprehension.

This paper presents a hypothesis-testing theory of syntax acquisition. The first section presents our model. We claim that: (1) children learn a transformational grammar, including a set of phrase structure and transformational rules; (2) linguistic universals and Occam's razor constrain the initial hypothesis space available to the device; (3) hypotheses tested by the device consist of candidate phrase structure and transformational rules; (4) linguistic evidence confirms or disconfirms hypotheses. Specific examples of incorrect phrase structure and transformational hypotheses are presented.

The second section briefly surveys other approaches to language acquisition – both syntactic and non-syntactic – and compares them to our model. In the third section, we address several methodological issues: (1) the relevance of linguistic theory to the model; (2) how the model is tested; (3) the domain of the theory.

This study aimed to investigate concerns of validity and reliability in subjective ratings of age-of-acquisition (AoA), through exploring characteristics of the individual rater. An additional aim was to validate the obtained AoA ratings against two corpora – one of child speech and one of adult speech – specifically exploring whether words over-represented in the child-speech corpus are rated with lower AoA than words characteristic of the adult-speech corpus. The results show that less than one-third of participating informants’ ratings are valid and reliable. However, individuals with high familiarity with preschool-aged children provide more valid and reliable ratings, compared to individuals who do not work with or have children of their own. The results further show a significant, age-adjacent difference in rated AoA for words from the two different corpora, thus strengthening their validity. The study provides AoA data, of high specificity, for 100 child-specific and 100 adult-specific Swedish words.

Despite the fact that in most communities interaction occurs between the child and multiple speakers, most previous research on input to children focused on input from mothers. We annotated recordings of Sesotho-learning toddlers living in non-industrial Lesotho in South Africa, and French-learning toddlers living in urban regions in France. We examined who produced the input (mothers, other children, adults), how much input was child directed, and whether and how it varied across speakers. As expected, mothers contributed most of the input in the French recordings. However, in the Sesotho recordings, input from other children was more common than input from mothers or other adults. Child-directed speech from all speakers in both cultural groups showed similar qualitative modifications. Our findings suggest that input from other children is prevalent and has similar features as child-directed from adults described in previous work, inviting cross-cultural research into the effects of input from other children.

Young Latino children of immigrants typically speak primarily Spanish at home and are exposed to varying amounts of English. As a result, they often enter school with a wide range of proficiencies in each language. The current study investigated family background, language use at home and early childhood settings as predictors of Spanish and English language proficiencies among Latino dual language children (N = 228). Findings demonstrated divergent sets of predictors were associated with either Spanish or English proficiencies at kindergarten and second grade. Sociocultural variables (parent origin, gender, home language use, home literacy practices, and language use in early childhood settings) predicted children's Spanish proficiency, while socioeconomic variables (poverty, and maternal and paternal education) predicted children's English proficiency, with little to no overlap in these predictions. These results suggest that different supports are required for proficiency in Spanish and in English, highlighting the importance of sociocultural and socioeconomic factors.

Evidence produced by Chomsky (1969) has suggested that 5-year-old children comprehend the verb tell more easily than the verb ask. This paper analyses the interpersonal context of appropriate use of these verbs and reports the results of two comprehension experiments with 5-year-olds. The first experiment, in attempting to correct an apparent methodological weakness in Chomsky's study, reverses her results and elicits a significantly higher frequency of correct responses to the verb ask than the verb tell: the second experiment demonstrates that this age group can consistently identify the speech acts to which the words ask and tell refer. The results are interpreted as support for the conclusion that 5-year-olds can comprehend the meaning of ask and tell, but that their linguistic comprehension is easily dominated by contextual and interpersonal expectations.

Two studies investigated syntactic productivity in three-year-old Mandarin speakers' use of verbs in the SVO and SbaOV constructions. In Study 1, children were taught novel verbs in one construction and assessed for their production in the other construction. Children produced verbs taught in the ba constructions in SVO utterances, but showed order effects when producing verbs taught in SVO constructions in ba utterances. In Study 2, children described animated scenes either with structural priming (i.e., after hearing verbs in SVO or ba constructions). Children demonstrated structural priming, producing more SVO and ba utterances, respectively, directly after hearing verbs in these constructions. These results indicate that Mandarin speaking three-year-olds demonstrate productive knowledge of both SVO and SbaOV constructions. Their ability to override the predominant input frequency of SVO runs counter to a purely usage-based account of early acquisition of grammar.