This study tested the claim of input-based accounts of language acquisition that children's inflectional errors reflect competition between different forms of the same verb in memory. In order to distinguish this claim from the claim that inflectional errors reflect the use of a morphosyntactic default, we focused on the Japanese verb system, which shows substantial by-verb variation in the frequency distribution of past and nonpast forms. 22 children aged 3;2–5;8 (Study 1) and 26 children aged 2;7–4;11 (Study 2) completed elicited production studies designed to elicit past and nonpast forms of 20 verbs (past-biased and nonpast-biased). Children made errors in both directions, using past forms in nonpast contexts, and vice versa, with the likelihood of each determined by the frequency bias of the two forms in the input language, even after controlling for telicity. This bi-directional pattern provides particularly direct evidence for the role of frequency-sensitive competition between stored forms.

This study examined the roles of parental gender and context in the communicative functions of parents’ child-directed speech. Seventy three families with toddlers participated in the study. Dyadic and triadic parent-toddler interactions were videotaped during structured play activities. Results indicated context-dependent variability in parents’ facilitative speech and gentle guidance. Parental gender effects were observed in parents’ directive speech but no gender or contextual effects were observed in parents’ referential speech. Results suggest the need for a closer examination of parental gender and contextual factors related to parents’ speech functions.

Children's remarkable ability to generalize beyond the input and the resulting overregularizations/ irregularizations provide a platform for a discussion of whether morphology learning uses analogy-based, rule-based, or statistical learning procedures. The present study, testing 115 children (aged 3 to 10) on an elicited production task, investigated the acquisition of the irregular distribution in the Turkish causative. Results showed that in early acquisition, to pin down the four causative suffixes, children engaged in comparisons between analogous exemplars. Thereafter to tackle the irregularity in two of the suffixes, children entertained competing hypotheses that yielded overregularizations and irregularizations. Overregularizations were instances of abstraction across the input based on type frequency; irregularizations were attempts to default to erroneous micro-generalizations. Negative correlation between errors and verb frequency suggested that recovery from errors was sensitive to token frequency. The overgeneralize-then-recover pattern that emerged in the acquisition of causative supported an integrated account of the roles of analogy, abstraction, and frequency in morphology learning.

This research brings new evidence on early lexical acquisition in Wichi, an under-studied indigenous language in which verbs occupy a privileged position in the input and in conjunction with nouns are characterized by a complex and rich morphology. Focusing on infants ranging from one- to three-year-olds, we analyzed the parental report of infants’ vocabulary (Study 1) and naturalistic speech samples of children and their caregivers (Study 2). Results reveal that: (1) although verbs predominate in the linguistic input, children's lexicons favor nouns over verbs; (2) children's early noun-advantage decreases, coming into closer alignment with the patterns in the linguistic input at a MLU of 1.5; and (3) this early transition is temporally related to children's increasing productive command over the grammatical categories that characterize the morphology of both nouns and verbs. These findings emphasize the early effects of language-specific properties of the input, broadening the vantage point from which to view the lexical acquisition process.

This review describes a computational approach for modeling the development of speech motor control in infants. We address the development of two levels of control: articulation of individual speech sounds (defined here as phonemes, syllables, or words for which there is an optimized motor program) and production of sound sequences such as phrases or sentences. We describe the DIVA model of speech motor control and its application to the problem of learning individual sounds in the infant’s native language. Then we describe the GODIVA model, an extension of DIVA, and how chunking of frequently produced phoneme sequences is implemented within it.

We assessed the effect of specificity of speaker information about an object on three-year-olds' word mappings. When children heard a novel label followed by specific information about an object at exposure, children subsequently mapped the label to that object at test. When children heard only specific information about an object at exposure, they inferred that the label applied to a different object at test. Finally, non-specific information did not assist children in mapping a word to an object. Thus, children use speaker information as a word-mapping cue but this information is interpreted differently depending on how the discourse is initiated.

Three- and four-year-old children were tested on their comprehension of the locative prepositions in front of, in back of, ahead of, and behind. Results demonstrated that those prepositions characterized as positive by H. Clark (1973) were, contrary to theoretical predictions, comprehended more poorly than their ostensibly negative counterparts. Discussion of the possible reasons for these findings is included.

Child partners were compared on their relative tendency to use the interrogative form in spontaneous dyadic verbal interactions. A given child's tendency to use the interrogative form more frequently than the other member of the dyad remained constant across partners. This relative stability in formulating utterances in interrogative form cannot be attributed to the child's producing more talk in general than the partner. The observed effect is explained as a type of conversational synchrony in which participants achieve a complementary balance rather than congruence. It was concluded that the interrogative form is a linguistic means for child peers to establish cooperation as well as controlling kinds of relationships during an ongoing interaction.

We investigated how Central Swedish-speaking four to eleven-year-old children acquire the prosodic marking of narrow focus, compared to adult controls. Three measurements were analysed: placement of the prominence-marking high tone (prominence H), pitch range effects of the prominence H, and word duration. Subject-verb-object sentences were elicited in sentence-medial and sentence-final focus conditions via a semi-spontaneous elicitation task. The children largely performed in an adult-like manner already at four to five: they predominantly added prominence H to focal words and avoided this tone post-focally in both sentence-medial and sentence-final position. The placement or avoidance of prominence H had largely the same effects on pitch range for children and adults. Finally, the four to eight-year-olds also increased the duration of the focal word, similar to adults. Hence, Central Swedish-speaking children master the use of prosody for focus marking at an earlier age, compared to children acquiring a West Germanic language.

Kindergarteners, grouped according to number conservation ability, were asked to explain their choices of more and less in a series of parallel tasks requiring comparative judgements of continuous quantities. Errors on less tasks, as well as correct choices of more, were often determined by the non-linguistic strategy of choosing the greater amount. Non-conservers were more likely than conservers or transitional conservers to rely on this strategy. Furthermore, mature semantic knowledge of more was found to precede the development of a similar understanding of less. Non-conservers were less likely than conservers or transitionals to have a mature understanding of either term.

The concern of this case study is to show how the parental terms for ‘mummy’ and ‘daddy’ in Latvian are acquired, paying particular attention to the changing relationship between the input and output forms during the acquisition process. We may note here three questions which we shall attempt to answer. (1) Are parental terms the earliest words used spontaneously by the young child? (2) Does their ‘easier’ word structure allow the child to acquire the adult forms for these words earlier than is the case for the rest of the vocabulary? (3) Do the function and meaning of these parental terms correspond to those of the adults', and if not, what is the difference? And how stable are the meanings of these words during the first years of life?

This paper seeks to account for a culturally patterned set of analogic renamings found in Huli baby talk, nursery rhymes and children's verbal games. These socialization activities evidence a marked concern with body motifs and appellations. In accordance with ethnographic paradigms of explanation, the frame of reference is broadened to include consideration of inter-adult behaviour involving ‘talk about the body’ to assess what is being learnt from such interactions as well as what communicative intents are encoded. The argument is developed that in addition to the significance of these play routines in sensitizing the child to cultural rules about speaking, these ludic forms also appear implicated in both an evolutionary and logico-operational sense in the conventional anatomical nomenclature.

Carol Stoel-Gammon has made a real contribution in bringing together two fields that are not generally jointly addressed. Like Stoel-Gammon, we have long focused on individual differences in phonological development (e.g. Vihman, Ferguson & Elbert, 1986; Vihman, Boysson-Bardies, Durand & Sundberg, 1994; Keren-Portnoy, Majorano & Vihman, 2008). And like her, we have been closely concerned with the relationship between lexical and phonological learning. Accordingly, we will focus our discussion on two areas covered by Stoel-Gammon (this issue) on which our current work may shed some additional light.

We examined the relation between maternal responsiveness and children's acquisition of mental and non-mental state vocabulary in 59 pairs of mothers and children aged 10 to 26 months as they engaged in a free-play episode. Children wore a head camera and responsiveness was defined as maternal talk that commented on the child's actions (e.g., when the child reached for or manipulated an object visible in the head camera). As hypothesized, maternal responsiveness correlated with both mental and non-mental state vocabulary acquisition in younger children (approximately 18 months and younger) but not older children. We posit a diminishing role for maternal responsiveness in language acquisition as children grow older.

The looking-while-listening (LWL) paradigm is frequently used to measure toddlers’ lexical processing efficiency (LPE). Children's LPE is associated with vocabulary size, yet other linguistic, cognitive, or social skills contributing to LPE are not well understood. It also remains unclear whether LPE measures from two types of LWL trials (target-initial versus distractor-initial trials) are differentially associated with the abovementioned potential correlates of LPE. We tested 18- to 24-month-olds and found that children's word learning on a fast-mapping task was associated with LPE measures from all trials and distractor-initial trials but not target-initial trials. Children's vocabulary and pragmatic skills were both associated with their fast-mapping performance. Executive functions and pragmatic skills were associated with LPE measures from distractor-initial but not target-initial trials. Hence, LPE as measured by the LWL paradigm may reflect a constellation of skills important to language development. Methodological implications for future studies using the LWL paradigm are discussed.

Linguistic input in multi-lingual/-cultural contexts is highly variable. We examined the production of English and Malay laterals by fourteen early bilingual preschoolers in Singapore who were exposed to several allophones of coda laterals: Malay caregivers use predominantly clear-l in English and Malay, but their English coda laterals can also be l-less (vocalised/deleted) and in formal contexts, velarised. Contrastingly, the English coda laterals of the Chinese majority are typically l-less. Findings show that English coda laterals were overall more likely to be l-less than Malay laterals like their caregivers’, but English coda laterals produced by children with close Chinese peer(s) were more likely to be l-less than those without. All children produced English coda clear-l, demonstrating the transmission of an ethnic marker that had emerged from long-term contact. In diverse settings, variation is intrinsic to the acquisition process, and input properties and language experience are important considerations in predicting language outcomes.

Many recent generativist models attribute grammatical knowledge to young children on the basis that children's language patterns the same way as the target adult language. It has been proposed that the child acquires this knowledge early on in development by a process of parameter setting. Wexler (1996) presents the VERY EARLY PARAMETER SETTING HYPOTHESIS (VEPS), which suggests that basic language-specific parameters are set correctly at the earliest observable stages, that is, from the onset of multi-word speech. However, the patterns predicted by VEPS are necessarily a characteristic feature of the input language and could therefore be just as readily explained in more limited scope terms. A good example of this is French negation where, in order to perform correctly, the child simply has to register that certain lexical forms precede the negative particle pas and certain other forms follow it. One implication of such a limited scope account is that there should be a strong relation between the lexical specificity of children's and mothers' use of verbs before and after pas. We present data for one subject, aged from 2;1 to 2;8, that are compatible with this hypothesis. While these data do not count directly against VEPS, they do suggest that the very low frequency of errors in children's use of French negation does not in and of itself constitute evidence for early syntactic knowledge.

Children with SLI have difficulty with tense and agreement morphology. This study examined the proficiency of these children and their typically developing peers with the coordination of tense and aspect markers in two-clause sentences. Scenarios designed to elicit past tense were presented to five- to eight-year-old children with SLI (n=14) and their normally developing age- and MLU-matched peers (n=24) to examine the omission of tense markers in complex sentences (Owen, 2010). Responses with overt tense/aspect morphology in both clauses were recoded for how similar the use of tense and aspect was across the two clauses. Tense and aspect concordance was high across both sentence types, but aspect-only mismatches were more common than tense mismatches. The three groups of children did not differ from each other on any comparisons. Coordination of temporal information in sentences with more than one time marker does not appear to be especially difficult for these children.