Recursive NPs are difficult to produce and late to emerge. We compare prosodic and syntactic abilities in Japanese-speaking five- and six-year-olds (n = 28) and adults (n = 10). It is reported that syntactic structure in Japanese is prosodically marked via downstep and metrical boost. Results of an elicited imitation task suggested that children had acquired the lexical prosody (contrast between accented and unaccented words), a pre-requisite for downstep realization. While downstep, the prosodic phrasing involved in the complex NPs in this study, was established, children showed interspeaker variation with the metrical boost, a feature that distinguishes recursively embedded NPs from non-recursive NPs. However, variability was also found in adults, indicating that, in contrast to previous results, prosodic encoding of syntax is generally unreliable in adult speech. Finally, the magnitude of metrical boost was not correlated to children's ability to produce recursive possessives, suggesting that prosody does not help bootstrap Japanese children's recursive phrases.

The outstanding property of human language is its diversity, and yet acquisition data is only available for three percent of the world's 6000+ spoken languages. Due to the rapid pace of language loss, it may not be possible to document how children acquire half of the world's indigenous languages in as little as two decades. This loss permanently diminishes the scope of acquisition theory by removing its empirical base. In the face of pervasive language loss, the question of how best to document the language of the last children to acquire indigenous languages assumes critical importance. A collaborative effort by researchers is required to identify the most efficient procedures for documenting children's language, and share them worldwide. This paper makes the case for documenting diversity and outlines steps needed to accomplish this goal.

We investigated whether children's inhibitory control (IC) is associated with their ability to produce irregular past tense verb forms as well as learn from corrective feedback following overregularization errors. Forty-eight 3;6 to 4;5 year old children were tested on the irregular past tense and provided with adult corrective input via models of correct use or recasts of errors following ungrammatical responses. IC was assessed with a three-item battery of tasks that required suppressing a prepotent response in favor of a non-canonical one. Results showed that IC was associated with children's initial production of irregular forms, but not associated with their post-feedback production. Findings are discussed in terms of current theories of past tense use and acquisition.

Naming semantically related images results in progressively slower responses as more images are named. There is considerable documentation in adults of this phenomenon, known as cumulative semantic interference. Few studies have focused on this phenomenon in children. The present research investigated cumulative semantic interference effects in school-aged children. In Study 1, children named a series of contiguous, semantically related pictures. The results revealed no cumulative interference effects. Study 2 utilized an approach more closely aligned with adult methods, incorporating intervening, unrelated items intermixed with semantically related items within a continuous list. Study 2 showed a linear increase in reaction time as a function of ordinal position within semantic sets. These findings demonstrate cumulative semantic interference effects in young, school-aged children that are consistent with experience-driven changes in the connections that underlie lexical access. They invite further investigation of how children's lexical representation and processing are shaped by speaking experiences.

Categorical induction abilities are robust in typically developing (TD) preschoolers, while children with Autism Spectrum Disorders (ASD) frequently perform inconsistently on tasks asking for the transference of traits from a known category member to a new example based on shared category membership. Here, TD five-year-olds and six-year-olds with ASD participated in a categorical induction task; the TD children performed significantly better and more consistently than the children with ASD. Concurrent verbal and nonverbal tests were not significant correlates; however, the TD children's shape bias performance at two years of age was significantly positively predictive of categorical induction performance at age five. The shape bias, the tendency to extend a novel label to other objects of the same shape during word learning, appears linked with categorical induction ability in TD children, suggesting a common underlying skill and consistent developmental trajectory. Word learning and categorical induction appear uncoupled in children with ASD.

Our motivation was to examine how toddler (2;6) and adult speakers of American English prosodically realize information status categories. The aims were three-fold: 1) to analyze how adults phonologically make information status distinctions; 2) to examine how these same categories are signaled in toddlers’ spontaneous speech; and 3) to analyze the three primary acoustic correlates of prosody (F0, intensity, and duration). During a spontaneous speech task designed as an interactive game, a set of target nouns was elicited as one of three types (new, given, corrective). Results show that toddlers primarily used H* across information status categories, with secondary preferences for deaccenting given information and for using L+H* for corrective information. Only duration distinguished information status, and duration, average pitch, and intensity differentiated pitch accent types for both adults and children. Discussion includes how pitch accent selection and input play a role in guiding prosodic realizations of information status.

This study investigated the acquisition of word-patterns and roots in the nominal system of the spoken language of Palestinian Arabic (PA) and its distance from Standard Arabic (StA). It described, analyzed, and quantified the nominal system (roots and word-patterns) as reflected in the language corpus of Palestinian-Arab kindergarteners 3 to 6 years old. The results showed that non-linear derived nouns (deverbal nouns) are the most frequently used category (49.5%). Primitive nouns comprise 43.1% of the nouns, whereas linear derived nouns barely exist before children start school (0.3%). Additionally, the results showed that half of the nouns were built from common word-patterns and roots between PA and StA, whereas 30% of the nouns were constructed from different word-patterns with common roots. Although PA and StA have much in common morphologically, there exists a significant degree of divergence.

Do parents fine-tune the MLU of utterances with a particular word as the word is on the verge of appearing in the child's production? We analyzed a corpus of spontaneous interactions of 30 dyads. The children were in the initial stages of their lexical development, and the parents’ utterances containing the words the children eventually acquired were selected. The main finding is that the MLU of the parental utterances containing the target words gradually decreased up to the point of the children's first production of those words. This suggests that parents fine-tune their utterances to support the children's linguistic development.

Laboratory observations are a mainstay of language development research, but transcription is costly. We test whether speech recognition technology originally designed for day-long contexts can be usefully applied to this use-case. We compared automated adult word and child vocalization counts from Language Environment Analysis (LENATM) to those of transcribers in 20-minute play sessions with Spanish-speaking dyads (n = 104) at 1;7 and 2;2. For adult words, results indicated moderate associations but large absolute differences. Associations for child vocalizations were weaker with larger absolute discrepancies. LENA has moderate potential to ease the burden of transcription in some research and clinical applications.

Previous comprehension studies using Picture Matching Tasks (PMT) have shown that, by the age of four, Spanish-speaking children have acquired the semantics of estar being able to calculate the implicature that a property introduced with estar does not hold independent of time as well as displaying some ability to integrate discourse information about properties that change in the course of a story. This study extends that line of research to children under the age of four. Thirty-eight monolingual Spanish-speaking children were tested in two PMTs. The results show that at age three children differ from older children in their interpretation of the copulas suggesting that the distinction between ser and estar with adjectives emerges between the ages of three and four.

This research investigates selectivity in word learning for bilingual infants. Previous work demonstrated that bilingual infants show greater openness to non-native language sounds in object labels than monolinguals (Hay et al., 2015; Singh, 2018). It remains unclear whether bilingual openness extends to nonspeech sounds. We presented 14- and 19-month-old bilinguals with object labels consisting of nonspeech tones. Monolinguals recently displayed learning of the same labels at 14 months, but not 19 months (Graf Estes et al., 2018). In contrast, bilinguals failed to learn the labels. We propose that hearing phonological variation across two languages helps bilinguals reject nonspeech word forms.