Children acquiring Japanese differ from those acquiring English with regard to the rate at which verbs are learned (Fernald & Morikawa, 1993). One possible explanation is that Japanese caregivers use verbs in referentially transparent contexts, which facilitate the form-meaning link. We examined this hypothesis by assessing differences in verb usage by Japanese and American caregivers during dyadic play with their infants (5-22 months). We annotated verb-containing utterances for elements associated with referential transparency and compared across groups. Contrary to our hypotheses, we found that Japanese caregivers used verbs in fewer referentially transparent contexts than American caregivers, or did not significantly differ from American caregivers, depending on the measure. These findings cast doubt on cross-cultural differences in referential transparency between Japanese and American child-directed input.

We present an exploratory cross-linguistic analysis of the quantity of target-child-directed speech and adult-directed speech in North American English (US & Canadian), United Kingdom English, Argentinian Spanish, Tseltal (Tenejapa, Mayan), and Yélî Dnye (Rossel Island, Papuan), using annotations from 69 children aged 2–36 months. Using a novel methodological approach, our cross-linguistic and cross-cultural findings support prior work suggesting that target-child-directed speech quantities are stable across early development, while adult-directed speech decreases. A preponderance of speech from women was found to a similar degree across groups, with less target-child-directed speech from men and children in the North American samples than elsewhere. Consistently across groups, children also heard more adult-directed than target-child-directed speech. Finally, the numbers of talkers present in any given clip strongly impacted children’s moment-to-moment input quantities. These findings illustrate how the structure of home life impacts patterns of early language exposure across diverse developmental contexts.

The purpose of the current study was to revisit a controversial topic: whether frequencies of phonological consonant and vowel classes differ in speech directed to children and to adults. In addition, the current study investigated whether the frequency of phonological consonant and vowel classes changes with children’s increasing chronological and/or developmental age. This study analyzed speech input from 44 adults to four different age groups of listeners (i.e., three groups of children at 6, 18, and 36 months of age and one group of adult listeners) in terms of frequency of occurrence of consonant and vowel classes. Results revealed that consonant stop, nasal, fricative and glide manner classes as well as all four consonant place classes were significantly different in speech directed to the four different age groups. A perspective is discussed to better understand the nature of frequency input of phonological sound classes.

Language in touchscreen apps could be useful as an additional source of children’s language input, alongside child directed speech (CDS) and books. Here we performed the first analysis of language in apps, as compared with books and CDS. We analysed language in 18 of the most popular educational apps targeting pre-schoolers and compared their language content to children’s books and CDS with respect to types of constructions and psycholinguistic features of words. We found that apps contained lower frequency words and had lower lexical diversity compared to CDS, and shorter utterances compared to books. Apps may thus provide an enriched supplementary form of input for young children, due to containing less frequent words. However, apps do not expose children to a high proportion of questions and complex sentences, both of which are crucial for supporting child’s development of structurally rich constructions.

As written language contains more complex syntax than spoken language, exposure to written language provides opportunities for children to experience language input different from everyday speech. We investigated the distribution and nature of relative clauses in three large developmental corpora: one of child-directed speech (targeted at pre-schoolers) and two of text written for children – namely, picture books targeted at pre-schoolers for shared reading and children’s own reading books. Relative clauses were more common in both types of book language. Within text, relative clause usage increased with intended age, and was more frequent in nonfiction than fiction. The types of relative clause structures in text co-occurred with specific lexical properties, such as noun animacy and pronoun use. Book language provides unique access to grammar not easily encountered in speech. This has implications for the distributional lexical-syntactic features and associated discourse functions that children experience and, from this, consequences for language development.

In an increasingly diverse society, young children are likely to speak different first languages that are not the majority language of society. Preschool might be one of the first and few environments where they experience the majority language. The present study investigated how preschool teachers communicate with monolingual English preschoolers and preschoolers learning English as an additional language (EAL). We recorded and transcribed four hours of naturalistic preschool classroom activities and observed whether and how preschool teachers tailored their speech to children of different language proficiency levels and linguistic backgrounds (monolingual English: n = 13; EAL: n = 10), using a suite of tools for analysing quantity and quality of speech. We found that teachers used more diverse vocabulary and more complex syntax with the monolingual children and children who were more proficient in English, showing sensitivity to individual children’s language capabilities and adapting their language use accordingly.

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.

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.

The rate at which young children are directly spoken to varies due to many factors, including (a) caregiver ideas about children as conversational partners and (b) the organization of everyday life. Prior work suggests cross-cultural variation in rates of child-directed speech is due to the former factor, but has been fraught with confounds in comparing postindustrial and subsistence farming communities. We investigate the daylong language environments of children (0;0–3;0) on Rossel Island, Papua New Guinea, a small-scale traditional community where prior ethnographic study demonstrated contingency-seeking child interaction styles. In fact, children were infrequently directly addressed and linguistic input rate was primarily affected by situational factors, though children's vocalization maturity showed no developmental delay. We compare the input characteristics between this community and a Tseltal Mayan one in which near-parallel methods produced comparable results, then briefly discuss the models and mechanisms for learning best supported by our findings.

Many children learn language, in part, from the speech of non-native speakers who vary in their language proficiency. To investigate the influence of speaker proficiency on the quality of child-directed speech, 29 mothers who were native English speakers and 31 mothers who were native speakers of Spanish and who reported speaking English to their children on a regular basis were recorded interacting with their two-year-old children in English. Of the non-native speakers, 21 described their English proficiency as ‘good’, and eight described their English proficiency as ‘limited’. ANCOVAs, controlling for differences in maternal education and child language level, revealed significant effects of group on lexical and grammatical properties of child-directed speech that the literature has identified as positive predictors of child language development. These results suggest that the child-directed speech of native speakers and non-native speakers with good proficiency provide a richer database for language acquisition than the child-directed speech of speakers with limited proficiency.

Adjectives are essential for describing and differentiating concepts. However, they have a protracted development relative to other word classes. Here we measure three- and four-year-olds’ exposure to adjectives across a range of interactive and socioeconomic contexts to: (i) measure the syntactic, semantic, and pragmatic variability of adjectives in child-directed speech (CDS); and (ii) investigate how features of the input might scaffold adjective acquisition. In our novel corpus of UK English, adjectives occurred more frequently in prenominal than in postnominal (predicative) syntactic frames, though postnominal frames were more frequent for less-familiar adjectives. They occurred much more frequently with a descriptive than a contrastive function, especially for less-familiar adjectives. Our findings present a partial mismatch between the forms of adjectives found in real-world CDS and those forms that have been shown to be more useful for learning. We discuss implications for models of adjective acquisition and for clinical practice.

Quantity and quality of input affect language development, but input features also depend on the context of language emission. Previous research has described mother-child interactions and their impact on language development according to activity types like mealtimes, book reading, and free play. Nevertheless, few studies have sought to quantify activity types in naturalistic datasets including less-studied languages and cultures. Our research questions are the following: we ask whether regularities emerge in the distribution of activity types across languages and recordings, and whether activities have an impact on mothers' linguistic productions. We analyse input for two children per language, at three developmental levels. We distinguish three activity types: solitary, social and maintenance activities, and measure mothers' linguistic productions within each type. Video-recorded activities differ across families and developmental levels. Linguistic features of child-directed speech (CDS) also vary across activities – notably for measures of diversity and complexity – which points to complex interactions between activity and language.

Socio-economic status (SES) impacts the amount and type of input children hear in ways that have developmental consequences. Here, we examine the effect of SES on the use of variation sets (successive utterances with partial self-repetitions) in child-directed speech (CDS). Variation sets have been found to facilitate language learning, but have been studied only in higher-SES groups. Here, we examine their use in naturalistic speech in two languages (Hebrew and English) for both low- and high-SES caregivers. We find that variation sets are more frequent in the input of high-SES caregivers in both languages, indicating that SES also impacts structural properties of CDS.

The prescriptive infinitive can be found in the North Germanic languages, is very old, and yet is largely unnoticed and undescribed. It is used in a very limited pragmatic context of a pleasant atmosphere by adults towards very young children, or towards pets or (more rarely) adults. It has a set of syntactic properties that distinguishes it from the imperative: Negation is pre-verbal, subjects are pre-verbal, subjects are third person and are only expressed by lexical DPs, not personal pronouns. It can be found in modern child language corpora, but probably originated before ad 500. The paper is largely descriptive, but some theoretical solutions to the puzzles of this construction are proposed.

Adult speakers constantly offer young children new terms, conventional words for the events and objects being talked about. They make direct offers of unfamiliar words, using deictics or other forms that signal that the upcoming term is new, and they make indirect offers on the assumption that the relevant meaning is computable on that occasion. Adults also present young children with information about how words are related to each other through such connections as is a part of, is a kind of, belongs to, or is used for. These pragmatic directions provide children with essential information about language and language use as they make inferences about possible meanings for unfamiliar words. They also offer support for an alternative to constraints-based accounts of lexical acquisition by providing a conversation-based approach more consistent with the findings from spontaneous speech and from experimental results.

Adult speakers constantly offer young children new terms, conventional words for the events and objects being talked about. They make direct offers of unfamiliar words, using deictics or other forms that signal that the upcoming term is new, and they make indirect offers on the assumption that the relevant meaning is computable on that occasion. Adults also present young children with information about how words are related to each other through such connections as is a part of, is a kind of, belongs to, or is used for. These pragmatic directions provide children with essential information about language and language use as they make inferences about possible meanings for unfamiliar words. They also offer support for an alternative to constraints-based accounts of lexical acquisition by providing a conversation-based approach more consistent with the findings from spontaneous speech and from experimental results.