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.

This study investigates perception and production of the Catalan mid-vowel /e/-/ɛ/ contrast by two groups of 4.5-year-old Catalan–Spanish bilingual children, differing in language dominance. Perception was assessed with an XAB discrimination task involving familiar words and non-words. Production accuracy was measured using a familiar-word elicitation task. Overall, Catalan-dominant bilingual children outperformed Spanish-dominant bilinguals, the latter showing high variability in production accuracy, while being slightly above chance level in perception. No correlation between perception and production performance could be established in this group. The effect of language dominance alone could not explain the Spanish-dominant participants’ performance, but quality of Catalan input (native vs. accented speech) was identified as an important factor behind familiar-word production and the inaccurate representation of the target contrast in the lexicon of the bilinguals’ less-dominant language. More fine-grained measurements of experience-related factors are needed for a full understanding of the acquisition of challenging contrasts in bilingual contexts.

The present study examined the speech production of three-year-old Korean–English bilingual (KEB) children. English and Korean stops, as well as front vowels in both languages, were compared acoustically among the KEB children, then also measured against those of their age-equivalent monolingual counterparts. Evidence of distinctive phonetic categorization in bilingual children was more salient in vowels than in stops. Vowels and stops produced by the bilingual children were not significantly different from those of their monolingual counterparts. The findings suggest that, similar to other language domains, two linguistic systems are apparent in the phonetic production component of three-year-old KEB children, but that phonetic distinctiveness in production may not emerge holistically in an across-the-board fashion, appearing earlier in vowels than stops. Thus, the phonetic production systems of the two languages may develop with only limited interaction in simultaneous KEB children exposed to two languages at an early age.

In the present study we investigate the production of gesture, intonation, and eye-gaze within the proto-imperative behaviour of one English child aged 1;0 to 1;7. The study is based on the qualitative and quantitative analysis of the three behaviours. The results indicate a shift from reaching gestures to points, and from rising terminal pitch contours to non-rising contours. The analysis also highlights changes in eye-gaze to the co-participant over time. In addition we identify a significant relationship between pitch contour and gesture type within the sample, with points being more closely associated with non-rise intonation than reaching gestures. We suggest that the changes in proto-imperative behaviour signal a shift in the underlying representation of the function from a request for help to a demand for a particular object, and that this development paves the way for the subsequent conventional linguistic expression of the imperative function.

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.

Vocabulary input frequency influences age of acquisition, and is also an essential control for investigating the influence of other factors. We propose a new method of frequency estimation, self-report. 918 Danish-speaking parents of 12–36-month-old children estimated their frequency of use of 725 words. Self-report was substantially correlated with both language sample based frequencies (0.67) and frequencies of a large written corpus of Danish (0.58). Correlations within vocabulary categories between frequency and age of acquisition, restricted to words occurring in the language samples, were comparable for the two estimates. Overall, self-report based frequency estimates appear to have a promising degree of validity, which reflects their greatest strength, independence of the situation.

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.

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.

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.

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?

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.

Acquisition of regular inflectional suffixes is an integral part of grammatical development in English and delayed acquisition of certain inflectional suffixes is a hallmark of language impairment. We investigate the relationship between input frequency and grammatical suffix acquisition, analyzing 217 transcripts of mother–child (ages 1 ; 11–6 ; 9) conversations from the CHILDES database. Maternal suffix frequency correlates with previously reported rank orders of acquisition and with child suffix frequency. Percentages of children using a suffix are consistent with frequencies in caregiver speech. Although late talkers acquire suffixes later than typically developing children, order of acquisition is similar across populations. Furthermore, the third person singular and past tense verb suffixes, weaknesses for children with language impairment, are less frequent in caregiver speech than the plural noun suffix, a relative strength in language impairment. Similar findings hold across typical, SLI and late talker populations, suggesting that frequency plays a role in suffix acquisition.

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.

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.

Adult Spanish speakers generally know which form a determiner preceding a noun should have even if the noun is not in their lexicon, because Spanish demonstrates high predictability between determiner form and noun form (la noun-a and el noun-o). We asked whether young children learning Spanish are similarly sensitive to the correlation of determiner and noun forms, or whether they initially learn determiner–noun pairings one-by-one. Spanish–English bilingual children and adults repeated Spanish words and non-words preceded by gender congruous and incongruous determiners. If children learn determiner–noun pairings one-by-one, they should show a gender congruity effect only for words. In contrast with this prediction, both children and adults demonstrated congruity effects for words and non-words, indicating sensitivity to correlated morphophonological forms. Furthermore, both age groups showed more facility in producing phrases with nouns ending in -a, which are more frequent and predictable from the preceding determiner.

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.

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.