Multiple approaches – including observational and experimental – are necessary to articulate powerful theories of learning. Our field’s key questions, which rely on these varied methods, are still open. How do children perceive and produce language? What do they encounter in their linguistic input? What does the learner bring to the task of acquisition? Considerable progress has been made for the development of spoken English (especially by North American learners). Yet there is still a great deal to discover about how children in other populations proceed, especially populations in rural settings. To examine language learning in these populations, we need a multi-method approach. However, adapting and integrating methods, particularly experimental ones, to new settings can present immense challenges. In this paper, we discuss the opportunities and challenges facing researchers who aim to use a multimethodological approach in rural samples, and what the field of language acquisition can do to promote such work.

There has recently been an increased interest in studying the language development of non-western languages. This is not new - it began in 1960’s and continued into the 1980’s and 1990’s. The current renewed interest is much welcomed, and will benefit from many of the experimental methods and theoretical insights developed over the past decades.

In the target article, Cristia, Foushee, Aravena-Bravo, Cychosz, Scaff, and Casillas (2023) convincingly show the need to broaden the current language acquisition research base, not only in linguistic diversity, but also in terms of regions and cultural groups studied. In conducting acquisition research in understudied populations, such as in rural settings, the authors highlight the importance of using a multi-method approach. They present the challenges in adapting these methods to new settings and offer possible ways to promote this type of research. In this commentary, we extend the discussion to understudied urban communities, as we encounter several of the concerns raised in Cristia et al. when collecting observational and experimental language acquisition data from Metro Manila, Philippines. We first describe the community we study, the challenges and modifications needed for conducting research in this setting, and end with a discussion of possible strategies to promote research in communities with understudied populations.

Our knowledge and theories about language acquisition are skewed towards urban languages, and primarily English (Kidd & Garcia, 2022). Cristia and colleagues convincingly show that studies on the acquisition of rural languages are scarce. The authors suggest that in rural settings, combining experimental and observational approaches is critical to testing and sharpening our theories about language acquisition. Nevertheless, they also acknowledge the numerous challenges that make it difficult to conduct, analyse and publish this type of work.

There is a large consensus (e.g., Cristia, Foushee, Aravena-Bravo, Cychosz, Scaff & Casillas, 2023; Kidd & Garcia, 2022) that diversification in language acquisition research is needed. Cristia et al. (2023) convincingly argue for studying language acquisition in rural populations and recommend combining observational and experimental approaches in doing so. In this commentary, we identify that diversification efforts must also include children growing up in non-western urban societies and that combining experiments with more easy-to-obtain data on language exposure can be a solid method to start with.

Person-referring pronouns in the first and second person (I, your) have been viewed as signs of increasing social understanding in children due to their shifting reference properties. However, they are linguistically complex elements and might depend on general language development. We used longitudinal transcript data from Manchester corpus (12 children aged 2 to 3 years) to examine concurrent and predictive relations between pronouns, general language development (MLU), and social understanding (indexed by the use of mental state language). In the key analysis, social understanding but not general language was found to be a developmental precursor of first-, second- and third-person pronoun mastery. Results suggest that social understanding is needed for acquisition of all person reference, not only in first and second person. Results for first- and third-person pronouns were more similar than for second person, suggesting that social-cognitive demands of person reference go beyond shifting reference of first- and second-person.

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.

It is often assumed that pre-schoolers learn a second language (L2) with ease, even for structures that are absent in their L1, such as Mandarin-speaking pre-schoolers learning L2 English grammatical inflections (e.g., duck s , hors es ). However, while the results from Study 1 showed that such learners can imitate plural words (age = 3;5, N = 20), Studies 2 and 3 showed that they cannot yet generate or comprehend plural morphology (Study 2: age = 4;8, N = 20; Study 3: age = 4;1, N = 20), raising questions about when this is achieved. These findings have important implications for school readiness, as well as for identifying those at risk of developmental language disorders.

Children learning English as an additional language (EAL) are a diverse and growing group of pupils in England’s schools. Relative to their monolingual (ML) peers, these children tend to show lower receptive and expressive vocabulary knowledge in English, although interpretation of findings is limited by small and heterogeneous samples. In an effort to increase representativeness and power, the present study combined published and unpublished datasets from six cross-sectional and four longitudinal studies investigating the vocabulary development of 434 EAL learners and 342 ML peers (age range: 4;9–11;5) in 42 primary schools. Multilevel modelling confirmed previous findings of significantly lower English vocabulary scores of EAL learners and some degree of convergence in receptive but not expressive knowledge by the end of primary school. Evidence for narrowing of the gap in receptive knowledge was found only in datasets spanning a longer developmental period, hinting at the protracted nature of this convergence.

This study investigated the acquisition of demonstratives (e.g., this/that, here/there) by 45 children (1;0 – 4;11) learning Ticuna, an Indigenous Amazonian language with an unusually complex demonstrative system. I analyzed 89 10-minute samples from video recordings of child-caregiver interaction, examining how often children and caregivers produced each demonstrative type, as well as relationships among children’s age, children’s demonstrative production, and caregivers’ production. Caregivers’ demonstrative production displayed few relationships with children’s age or production. Children produced speaker-proximal and speaker-distal demonstratives (this near me, that far from me) earlier in developmental time than addressee-proximal demonstratives (that near you), and nominal (this/that) demonstratives earlier than locative (here/there) ones. Compared to caregivers, children overused speaker-proximal demonstratives, but used other demonstrative types with adult-like frequency beginning at 2;0. These results support the view that cognitive biases toward egocentric, proximal, and semantically simpler items substantially influence children’s acquisition of demonstratives.

Forty-eight toddlers participated in a word-learning task to assess gesture input on mapping nonce words to unfamiliar objects. Receptive fast mapping and expressive naming for target object-word pairs were tested in three conditions – with a point, with a shape gesture, and in a no-gesture, word-only condition. No statistically significant effect of gesture for receptive fast-mapping was found but age was a factor. Two year olds outperformed one year olds for both measures. Only one girl in the one-year-old group correctly named any items. There was a significant interaction between gesture and gender for expressive naming. Two-year-old girls were six times more likely than two-year-old boys to correctly name items given point and shape gestures; whereas, boys named more items taught with the word only than with a point or shape gesture. The role of gesture input remains unclear, particularly for children under two years and for toddler boys.

This longitudinal study investigated how lexical restructuring can stimulate emerging bilingual children’s phonological awareness in their first (L1) and second (L2) languages. Sixty-two English (L1) – French (L2) bilingual children (Mage = 75.7 months, SD = 3.2) were taught new English and French word pairs differing minimally in phonological contrast. The results indicated that increasing lexical specificity in English mediated the relationship between English vocabulary and English phonological awareness both concurrently and longitudinally at the end of Grade 1. A longitudinal relationship was established among French vocabulary, French lexical specificity, and French phonological awareness at the end of Grade 1. Notably, cross-language transfer from English lexical specificity was a better predictor of development in French phonological awareness, especially for words that contained phonological contrasts that occurred in both languages. The results from this study highlight the phonological foundations of early literacy and extend the lexical restructuring hypothesis to emerging bilingual children.

Young children often make pragmatic assumptions when learning new words. For example, they assume that a speaker who uses different words intends to refer to different things – the so-called principle of contrast. We used a standard disambiguation task to explore whether children’s assumptions about contrast depend on how much words differ. Three- to 6-year-olds heard pairs of words that differed in terms of the number, position, and types of phonological contrasts. Results indicate that children were less likely to disambiguate words differing by one phoneme than words differing by two or more phonemes, particularly when those one-phoneme differences were located at the beginning or end of the words (as in fim/vim). Overall, the findings suggest that children’s pragmatic assumptions about two contrasting words depend not only on if words differ, but also on how they differ.

This study investigated whether Korean children follow the acquisition pattern predicted by the Aspect Hypothesis (Shirai & Andersen, 1995), and the relationship between caretakers’ and children’s speech. Accordingly, we analyzed a Korean corpus (Ryu-Corpus) on the CHILDES database (MacWhinney, 2000), which comprised longitudinal video-recorded interactions of three Korean children and their caregivers. Results indicate that the children used the past marker -ess principally with telic verbs, consistent with the Aspect Hypothesis. Each child’s usage closely reflects the caretaker’s frequency, yielding a high correlation (τb = 0.79). However, the acquisition of the imperfective marker -ko iss did not show a predicted association with activity verbs, contrary to the Aspect Hypothesis. Furthermore, caretakers’ input did not correlate with the children’s utterances of the imperfective marker (τb = 0.40). We argue that multiple factors such as input frequency, language-specific organization of aspectual semantics, and individual differences should be considered to explain tense-aspect acquisition.

A growing body of research suggests that individual variation in young children’s word comprehension (indexed by response times and accuracy) is structured and meaningful. In this paper, we assess how children’s word comprehension correlates with three factors: socio-economic status (indexed by maternal education), lingual status (based on language exposure), and age. We present results from 91 2- to 3-year-old children using a paired forced-choice task built on a child-friendly touch screen. Effects associated with maternal education and exposure to the tested language (French) were small, and they were greater for accuracy than response times. This pattern of results is compatible with an interpretation whereby the greatest effects of these two variables are on cumulative knowledge (vocabulary size) rather than on processing. Effects for age were larger and affected both accuracy and response times. Finally, response time variation did not mediate the effects of socio-economic status on accuracy or vice versa.

Young children with Down syndrome (DS) have language delays beginning early in life. Book reading with parents provides a context for capitalizing on language learning opportunities. This study evaluated the quantity and quality of language input among mothers and fathers of young children with DS during book reading interactions and investigated associations with child language. Findings revealed that mothers were more talkative and used more descriptive language, whereas fathers spent more time reading the book text. Moreover, maternal and paternal input were correlated with different measures of child language, suggesting that mothers and fathers may use divergent approaches to support language development.