In the period between sole use of single words and majority use of multiword utterances, children draw from their existing productive capability and conversational input to facilitate the eventual outcome of majority use of multiword utterances. During this period, children use word combinations that are not yet mature multiword utterances, termed ‘successive single-word utterances’ (SSWUs). The language development of five children, observed in play with their mothers, was studied longitudinally across the transitional period (age 1 ; 3 to 2 ; 0). Results demonstrate a common developmental trajectory from single words to SSWUs, formed with the support of conversation, to more independent SSWUs, and finally to majority use of multiword utterances. The children varied in the extent to which they produced SSWUs and whether they first produced across-turn versus within-turn SSWUs. Possible reasons for variability and why SSWU production may be important to the development of multiword utterances are discussed.

Infants begin to understand some of the meanings of the adjective good at around thirteen months, but it is not clear when they start to map it to concepts in the moral domain. We investigated infants’ and toddlers’ knowledge of good in the domains of help and fairness. Participants at 20 and 30 months were shown computer animations involving helpful and hindering agents, or agents who performed fair or unfair distributions, and were asked to “pick the good one”. Toddlers at 30 months took good as referring to helping, but not to the fair agents. However, when asked “to pick one”, they choose the fair distributor. These findings suggest that by 30 months toddlers have started to map good to some socio-moral features, such as a helping disposition, but not to fairness in distributive actions.

Language is conceptualized as a multi-dimensional entity which involves symbolic and cognitive aspects, communicative aspects, and structural-linguistic aspects, both syntactic and semantic. The child's task during acquisition is to become aware of, to understand, and to operate according to convention in these three spheres. Analysis of the single-word production of three children revealed developmental changes in the salience of the three aspects and individual differences in functional styles of language acquisition. Use of the multi-dimensional approach also revealed differences in the relations between language, overt action, and a child's tendency to talk about action. Many differences, particularly in communicative style, were related to differences in parent–child interaction.

Children have to figure out the lexicalization of meaning components in learning verb semantics (e.g. Behrens, 1998; Gentner, 1982; Tomasello & Brooks, 1998). The meaning of an English state-change verb (e.g. break) is divided into two portions (i.e. cause and result), respectively encoded with a separate verb in a Mandarin resultative verb compound (RVC). The majority of Mandarin monomorphemic verbs do not specify any realization of a state change (like hunt), or only imply it (like wash) (Talmy, 2000). This study examines the acquisition of the constructional meaning of RVCs and the semantic division of labor between the component verbs. Four groups of Mandarin-learning children (aged 2;6, 3;6, 4;6, and 6;1) participated in an elicitation experiment. The results reveal that, although transparency in form facilitates their learning of the state-change meanings of RVCs, Mandarin children have difficulties in unpacking the meanings of individual verbs, revealing language-specific learning issues.

Distinctive feature specification and representation in phonological acquisition are examined in the context of underspecification theory. Subjects were 30 children (aged 3;1 to 5;10) who exhibited systematic differences in their linguistic knowledge of target phonological contrasts. A free classification task was used to tap children's conceptual knowledge of these contrasts, with features of place and manner experimentally manipulated. Three questions were addressed: which features do children use to categorize segmentai information, do the defining features of a category shift as the phonological system advances, and which framework of underspecification theory best accounts for the results? All children categorized segments on the basis of marked nonredundant featural properties, and used only one feature value to define category membership consistent with radical underspecification. Linguistic knowledge and linguistic input both influenced children's category judgements, but to different degrees. The emergence of phonological categories involved increasing feature differentiation as the child's productive phonology advanced.

Speakers often anticipate how recipients will interpret their utterances. If they wish some other, less obvious interpretation, they may ‘mark’ their utterance (e.g. with special intonations or facial expressions). We investigated whether two- and three-year-olds recognize when adults mark a non-verbal communicative act – in this case a pointing gesture – as special, and so search for a not-so-obvious referent. We set up the context of cleaning up and then pointed to an object. Three-year-olds inferred that the adult intended the pointing gesture to indicate that object, and so cleaned it up. However, when the adult marked her pointing gesture (with exaggerated facial expression) they took the object's hidden contents or a hidden aspect of it as the intended referent. Two-year-olds' appreciation of such marking was less clear-cut. These results demonstrate that markedness is not just a linguistic phenomenon, but rather something concerning the pragmatics of intentional communication more generally.

An allative bias has been noted in children's comprehension of deictic verbs and directional prepositions. This study investigates the allative bias and its susceptibility to contextual modification. Three-year-olds were asked to act according to requests to move one object to or from another, and to identify where an object had come from or gone to. A reliable bias was found whereby ‘to’ was easier than ‘from’. Attempts to make the utterance more naturally related to the task, by using movement and fronted objects, modulated the bias to a small extent, but did not abolish it. An analysis of directional expressions in terms of the components SOURCE, PATH and GOAL is presented in relation to the task-demands.

Rhotics, particularly the trill, are late acquired sounds in Spanish. Reports of Spanish–English bilingual preschoolers document age-appropriate articulations, but studies do not explore productions once exposure to English increases. This paper reports on the rhotic productions of a cross-sectional sample of 31 Spanish–English bilingual children, ages 6;8 to 13;5. Children produced taps with high rates of accuracy across age groups; the trill did not reach 80% target production until age 11;3, later than reported for monolingual speakers. Increased English exposure is explored as a contributing factor, arguing a need for continued study of bilingual phonological development beyond the preschool years.

Pierce et al. (2017) have proposed that variations in the timing, quality and quantity of language input during the earliest stages of development are related to variations in the development of phonological working memory and, in turn, to later language learning outcomes. To examine this hypothesis, three groups of children who are at-risk for language learning were examined: children with cochlear implants (CI), children with developmental language disorder (DLD), and internationally-adopted (IA) children, Comparison groups of typically-developing monolingual (MON) children and second language (L2) learners were also included. All groups were acquiring French as a first or second language and were matched on age, gender, and socioeconomic status, as well as other group-specific factors; they were between 5;0–7;3 years of age at time of testing. The CI and DLD groups scored significantly more poorly on the memory measures than the other groups; while the IA and L2 groups did not differ from one another. While the IA group performed more poorly than the MON group, there was no difference between the L2 and MON groups. We also found differential developmental relationships between phonological memory and language among the groups of interest in comparison to the typically-developing MON and L2 groups supporting the hypothesis that language experiences early in life are consequential for language development because of their effects on the development of phonological memory.

A boy's acquisition of Pig Latin was monitored throughout the year preceding first grade. Abilities underlying this game include the identification of words, deletion of the first syllabic onset (i.e. prevocalic consonants) of each word, blending of this onset and the suffix [e1] onto the word's end, and short-term memory for speech units. Performance improved over time as the underlying abilities developed. Meanwhile, various informative errors were made. Throughout most of the study, onsets that were correctly removed from a word's beginning were often added to its end incorrectly; unstressed function words were repeated intact and not transformed; and the first syllabic onset was overlooked when the syllable was unstressed. Because speech games like this one depend upon basic language skills, they can clarify aspects of ordinary language development.

Preschoolers participated in a modified version of the disambiguation task, designed to test whether the pragmatic environment generated by a reliable or unreliable speaker affected how children interpreted novel labels. Two objects were visible to children, while a third was only visible to the speaker (a fact known by the child). Manipulating whether a novel object was visible to both interlocutors or hidden from the child tested the child's understanding of pragmatic expectations of interlocutor competence. When interacting with a speaker with a history of accurately labeling familiar objects, children responded appropriately in both cases. Whn interacting with a speaker who previously generated inaccurate labels for familiar objects, children's behavior and eye-movements reflected their belief that the speaker was not a competent communicator. These data support the hypothesis that children consider the pragmatic environment constructed by an interlocutor when that speaker asks them to make a lexical inference.

Young children are conservative when extending novel verbs to novel exemplars. We investigated whether multiple, simultaneously presented exemplars would aid young children's verb learning, as well as the importance of exemplar variability. Three-year-olds were taught novel verbs, while viewing either one action-scene featuring a novel action performed on a novel object, or two action-scenes side-by-side in which the action performed was the same but the object varied, or two action-scenes side-by-side in which no aspect of the scenes varied. They were asked to extend the novel verbs to one of two scenes: one that maintained the action and one that maintained the object. Findings indicated that children were only able to extend verbs correctly after viewing two action-scenes in which the content varied. These findings suggest that simultaneously presented exemplars of a verb can support verb learning in younger children, but only when the content of the exemplars varies.

Previous studies on the role of vowel harmony in word segmentation are based on artificial languages where harmonic cues reliably signal word boundaries. In this corpus study run on the data available at CHILDES, we investigated whether natural languages provide a learner with reliable segmentation cues similar to the ones created artificially. We observed that in harmonic languages (child-directed speech to thirty-five Turkish and three Hungarian children), but not in non-harmonic ones (child-directed speech to one Farsi and four Polish children), harmonic vowel sequences are more likely to appear within words, and non-harmonic ones mostly appear across word boundaries, suggesting that natural harmonic languages provide a learner with regular cues that could potentially be used for word segmentation along with other cues.

Sensitivity to differences in lexical stress pattern was examined in 4- and 5-year-old monolingual French-, German- and Swedish-speaking children. For most stimulus discriminations, the 5-year-olds outperformed their 4-year-old comparison groups. For a discrimination involving a trisyllabic distinction not found in French, however, the French 5-year-olds performed worse than their 4-year-old compatriots, suggesting that the older children had ‘learned’ not to hear the trisyllabic distinction. In follow-up testing of the French 4-year-olds six months later, half of them showed a similar decrease in performance specific to the trisyllabic stimuli. These data support an ‘attunement’ theory of language acquisition, in which potentially relevant abilities that are already partially or fully developed at birth may become attenuated or completely lost if they are inappropriate or irrelevant for the child's language.

Goad & Ingram (1987) use the mere existence of inter-child variability to argue in favour of a ‘cognitive’, and against a ‘biological’ model of phonological development (Locke 1983). In this response it is suggested that such an argument fails to recognize the uniqueness of each individual's neural and vocal structures, ignores documented variability in the phonetic patterns of prelexical (and arguably prephonological) infants, and assumes–inexplicably–that inter-child variability implies the operation of ‘cognitive’ factors.

A recurring result from studies which relate the frequency of input variables to rate of language development, is the link between auxiliary verb growth and yes—no questions addressed to children. Explanations for this relationship usually concentrate on the advantages of hearing stressed and non-contracted auxiliary forms in sentence-initial position over hearing unstressed, contracted forms in medial position in declaratives. If such accounts are correct, then it can be predicted that yes—no questions which place forms of COPULA be in initial position will also increase the rate of growth of children's COPULA verb development. This prediction was tested using a sample of 33 children, carefully matched for stage of language development at 1;9 and 2;0 years; rate of copula verb growth was then measured over the succeeding nine months. Analyses include an examination of the contribution of sub-categories of yes—no question, tag questions, and utterances containing sentence-final copulas to the growth of contracted and full copulas. Results confirm that the frequency of inverted copulas in yes—no questions predicts children's copula development. Nevertheless, caution is urged before interpreting the relationship in terms of a direct causal model.

Gesture and prosody are considered to be important precursors in early language development. In the present study, we ask whether those cues play a similar role later in children's acquisition of more complex pragmatic skills, such as politeness. 64 three- to five-year-old Catalan-dominant children participated in a request production task in four different conditions. They were prompted to request an object from either a classmate or an unfamiliar adult experimenter, with the implied cost of the request to the receiver's face thus being either high or low. Results showed that these preschool-age children used mitigating prosodic and gestural strategies to encode politeness earlier and more often than they used lexical or morphosyntactic markers, and that those cues develop incrementally during the preschool years. These findings suggest that prosody, gesture, and other body signals are an essential first step in the development of children's socio-pragmatic competence.

A longitudinal study of one child aged 2;5 documents an invented language game consisting of suffixal reduplication and onset replacement. Initially, reduplication is partial: the reduplicant enlarges in discrete increments over the five stages of the game until by the last stage reduplication is total. Reduplication is accompanied by a process of onset replacement, in which the reduplicant always begins with /b/. Early in the game, this replacive onset ‘dissimilates’ to /p/ whenever the reduplicant would independently have begun with /b/. In subsequent stages, other voiced obstruents trigger dissimilation as well. Though similar in many ways to adult language reduplication, it is argued that J's game may more closely resemble adult rhyme (both poetic and word rhyme). Regardless, the structure of the game clearly reveals the child's awareness, in the third year of life, of stress and metrical feet, segmental natural classes, and segments themselves (phonemic awareness).