Languages employ different means to manifest the unaccusative-unergative distinction. In Mandarin Chinese, unaccusative verbs are allowed in the inversion construction “V-le NP”, while unergative verbs are not. This grammaticality contrast brings a presence/absence contrast between the two verb classes in the inversion construction in the input. Using an eye fixation task, we investigated whether Mandarin-learning 19-month-olds were sensitive to this specific input frequency contrast. We found that infants distinguished the grammatical versus ungrammatical uses of the two verb classes in the inversion construction “V-le NP” (Experiment 1). When the verb classes were in the “NP V-le” order (Experiment 2) (i.e., the same level of grammaticality), infants showed no evidence of a looking difference. These responses indicate toddlers’ sensitivity to the distribution of the two verb classes in the inversion construction. This distributional information is likely to be one of the potential cues that facilitate their acquisition of the unaccusative-unergative distinction.

Sentences that have more than one possible meaning are said to be syntactically ambiguous (SA). Because the correct interpretation of these sentences can be unclear, resolving SA sentences can be cognitively demanding for children, particularly with regards to inhibitory control (IC). In this study we provide three lines of evidence supporting the importance of IC in SA resolution. First, we show that children with higher IC resolve more SA sentences correctly. Second, we show that SA resolution is worse on tasks that place higher demands on IC, even for children with high IC. Third, we show that children with higher IC make different types of SA errors than children with lower IC. This study expands understanding of the cognitive skills underlying language and suggests a need to consider task demands on IC when developing educational curriculums.

We investigate whether child-directed speech (CDS) contains a higher proportion of canonical pronunciations compared to adult-directed speech (ADS), focusing on Korean noun stem-final obstruent variation. In a word-teaching task, we observed that mothers use a higher rate of canonical pronunciation when addressing infants than when addressing adults. In a follow-up experiment, adults exhibited a higher rate of canonical pronunciation for high- than low-frequency words. Additional analyses conducted with only the high-frequency monosyllabic words from the two experiments found no evidence for simplified phonology in CDS when lexical frequency was controlled for. Our findings suggest that the higher rate of canonical forms in CDS, with respect to Korean morphophonological rules, is mediated by the frequency of word usage. Thus, the didactic function of CDS phonology appears to be a byproduct of mothers using familiar words with children. These results highlight the importance of considering word usage in investigating the nature of CDS.

Research shows that infants and preschoolers can learn novel words equally well through addressed speech as through overhearing two adults. However, most of this research draws from samples of ethnic majority children. The current study compares word learning in preschoolers (M age = 5;6) with an ethnic minority and an ethnic majority background (N = 132). An experimenter of the majority group (representative for most teachers in Flemish education) told a story in three different interaction situations: Addressed Speech, Overhearing Classroom and Overhearing Two Adults. Results show that children of both ethnic groups learn novel words in Addressed Speech and in Overhearing Classroom equally well. However, minority children learned significantly fewer words in Overhearing Two Adults. This study suggests important differences in how ethnic majority and minority children learn through indirect speech in educational (monolingual) settings. In addition, the study scrutinizes the potential role of social identification in overhearing mechanisms.

This study compared school-aged monolingual and bilingual English-as-a-foreign-language (EFL) learners in terms of understanding metaphors on recall, multiple-choice, and reasoning tasks. It also examined the relationship between cognitive capacity and understanding metaphors on different measures. A hundred and thirty Persian–Turkish early bilinguals and 122 monolingual Persian-speaking EFL learners took three different tests of metaphor comprehension and the Figural Intersections Test, a test of cognitive capacity. Bilinguals outperformed monolinguals in terms of cognitive capacity and understanding metaphors on two of the tasks, though with a small effect size. Furthermore, there was a significant positive relationship between cognitive capacity and the scores on the multiple-choice and reasoning tests, but not the recall test. Results suggest that bilingual L3 learners have an edge in understanding metaphors, reflecting a cognitive advantage.

Parental input is considered a key predictor of language achievement during the first years of life, yet relatively few studies have assessed its effects on longer-term outcomes. We assess the effects of parental quantity of speech, use of parentese (the acoustically exaggerated, clear, and higher-pitched speech), and turn-taking in infancy, on child language at 5 years. Using a longitudinal dataset of daylong LENA recordings collected with the same group of English-speaking infants (N=44) at 6, 10, 14, 18, 24 months and then again at 5 years, we demonstrate that parents’ consistent (defined as stable and high) use of parentese in infancy was a potent predictor of lexical diversity, mean length of utterance, and frequency of conversational turn-taking between children and adults at Kindergarten entry. Together, these findings highlight the potential importance of a high-quality language learning environment in infancy for success at the start of formal schooling.

The present study explored developmental differences in preschoolers’ use of reported speech and internal state language in personal narratives. Three-, four-, and five-year-olds attending a laboratory preschool shared 204 stories about ‘a time when you were happy/sad’. Stories were audio-recorded, transcribed, and coded for reported speech (direct, indirect, narrativized) and internal state language (cognitive states, total emotion terms, unique emotion terms). Personal narratives told by five-year-olds included more cognitive states and more narrativized speech than those told by three- and four-year-olds, even when accounting for children’s vocabulary skills, and that reported speech (narrativized, direct) were positively correlated with cognitive state talk. These findings highlight distinct shifts in children’s use of cognitive state talk and reported speech in personal narratives told at age five. Associations between reported speech and internal state language are both informed by and support Vygotsky’s (1978) fundamental claim that psychological processes are socially mediated by language.

Pointing plays a significant role in communication and language development. However, in spoken languages pointing has been viewed as a non-verbal gesture, whereas in sign languages, pointing is regarded to represent a linguistic unit of language. This study compared the use of pointing between seven bilingual hearing children of deaf parents (Kids of Deaf Adults [KODAs]) interacting with their deaf parents and five hearing children interacting with their hearing parents. Data were collected in 6-month intervals from the age of 1;0 to 3;0. Pointing frequency among the deaf parents and KODAs was significantly higher than among the hearing parents and their children. In signing dyads pointing frequency remained stable, whereas in spoken dyads it decreased during the follow-up. These findings suggested that pointing is a fundamental element of parent-child interaction, regardless of the language, but is guided by the modality, gestural and linguistic features of the language in question.

The current study investigated whether vocabulary relates to phonetic categorization at neural level in early childhood. Electoencephalogram (EEG) responses were collected from 53 Dutch 20-month-old children in a passive oddball paradigm, in which they were presented with two nonwords “giep” [ɣip] and “gip” [ɣɪp] that were contrasted solely by the vowel. In the multiple-speaker condition, both nonwords were produced by twelve different speakers; while, in the single-speaker condition, one single token of each word was used as stimuli. Infant positive mismatch responses (p-MMR) were elicited in both conditions without significant amplitude differences. When the infants were median split based on vocabulary level, the large and small vocabulary groups showed comparable p-MMR amplitudes yet different scalp distribution in both conditions. These results suggest successful phonetic categorization of native similar sounding vowels at 20 months, and a close relationship between speech categorization and vocabulary development.

Typically-developing bilingual children often score lower than monolingual peers of the same age on standardized measures; however, research has shown that when assessed in more natural discourse contexts, bilinguals can perform similar to age-matched monolinguals in some language subdomains. This study investigated complex syntax production in simultaneous French–English bilingual children and monolingual age-matched peers, using structured and spontaneous measures. Surprisingly, the bilinguals scored higher than the monolinguals on the structured task. There was no difference between groups on the spontaneous measure; however, predictors of complex syntax production differed by language groups and by tasks. Contrary to other language subdomains showing bilingual English development as protracted relative to monolingual peers, these results point to a relative strength of complex syntax acquisition among simultaneous bilingual children. Differences in exposure relative to monolingual children may be less pronounced in syntax, in part because bilinguals can benefit from syntactic knowledge in their other language.

The current research examined whether children’s expectations about labeling conventions can be influenced by limited exposure to a foreign language. Three- to four-year-old Korean children were presented with two speakers who each assigned a novel label either in Korean or Spanish to a novel object. Children were asked whether both labels were acceptable for the object. Children who had more exposure to a foreign language through live social interaction, but not through media, were more likely to accept both Korean and Spanish labels. These findings indicate the influence of social interaction in foreign language exposure on children’s understanding of different labeling conventions.