Purpose: The goal of this work was to examine the semantic and syntactic properties of the vocabularies of autistic and non-autistic infants and toddlers to see if children in these two groups know different kinds of words. We focused on both receptive and expressive vocabularies. For expressive vocabulary, we looked only at the "active"…

Purpose: We examined the properties of mean length of utterance (MLU) in Czech, a morphologically complex Slavic language. We compared the scores of MLU calculated in different units and based on different sample lengths and assessed its validity against another transcript and test-based measures. Method: One hundred nine children were recorded…

The current study examined early grammatical marking in a relatively understudied language, Mandarin, by using the Mandarin version of MacArthur-Bates Communicative Development Inventory. Two waves of data collection included 338 monolingual children (17-36 months; 143 female) at Time 1 and 308 children (32-55 months; 139 female) at Time 2 and…

Purpose: This study presents a comprehensive exploration of lexical and grammatical development in Palestinian Arabic (PA). The study aims to test the validity of the Palestinian Arabic Communicative Development Inventory (PA-CDI) as well as generate growth curves for lexical and morphosyntactic development, examine the order of emergence of both…

To examine whether children's acquisition of perspective-marking language supports development in their ability to reason about mental states, we conducted a longitudinal study testing whether proficiency with complement clauses around age 3 explained variance in false-belief reasoning 6 months later. Forty-five English-speaking 2- and 3-year-olds…

Previous studies show that infants store functional morphemes for inferring syntactic categories of adjacent words, and they generally perform better with nouns than with verbs. In this study, we tested whether toddlers can exploit phrasal groupings for syntactic categorization in the face of noisy co-occurrence patterns. Using a visual fixation…

The study examines phases in developing specification of grammatical marking of emergent clause-combining (CC) as indicative of children's growing ability to integrate two or more independent predications. To this end, both intra- and inter-clausal analyses were applied to all CC utterances produced by three Hebrew-acquiring children aged 2;0-3;0,…

This study examines the role of the lexicon and grammatical structure building in early grammar. Parent-report data in CDI format from a sample of 1151 German-speaking children between 1;6 and 2;6 and longitudinal spontaneous speech data from 22 children between 1;8 and 2;5 were used. Regression analysis of the parent-report data indicates that…

Purpose: This article focuses on toddlers' revisions of the sentence subject and tests the hypothesis that subject diversity (i.e., the number of different subjects produced) increases the probability of subject revision. Method: One-hour language samples were collected from 61 children (32 girls) at 27 months. Spontaneously produced, active…

We examined French-learning toddlers' sensitivity to Subject-Verb agreement with conjoined subjects. In French, a conjoined NP triggers plural agreement even when made up of individual singular NPs. Processing of this infrequent structure in the input (see Corpus Analyses) requires going beyond surface patterns of non-adjacent dependencies to…

This paper revisits the longstanding observation that children produce modal verbs (e.g., must, could) with their root meanings (e.g., abilities, obligations) by age 2, typically a year or more earlier than with their epistemic meanings (e.g., inferences). Established explanations for this "Epistemic Gap" argue that epistemic language…

There is a debate as to whether topic structures in Chinese involve A'-movement or result from base-generation of the topic in the left periphery. If Chinese topicalization was derived by movement, under the assumptions of Friedmann et al.'s Relativized Minimality (Lingua 119:67-88, 2009), we would expect children's comprehension of object…

In this study, we explored the role of emerging inhibitory control skills in language acquisition in 62 typically developing children aged 24-32 months and investigated whether early inhibitory control skills are longitudinally associated with language outcome. Specifically, we focused on two different inhibitory processes that develop…

Early trilingual development is an excellent testing ground for input reduction effects on acquisition outcomes. This article reports a study investigating input-outcome relations in a child Leo in Hong Kong, who was addressed to in Mandarin, Cantonese and later also in English by caretakers through 'one caretaker-one language' and 'one day-one…

Spontaneous verbal repetition is part of early adult-child conversational interchanges. However, most of the studies devoted to verbal repetition analyse child-produced and adult-produced repetition independently. The aim of this study is to analyse verbal repetition sequences that are extended by children and adults participating in turns. We…