Toddlers learn more about the world from picture books with photographs instead of drawings, but commercial books often have tactile features such as flaps that may counterintuitively hinder learning. This study tested how lift-the-flap features in a commercial picture book of first words affected 2-year-olds' (N = 32) learning of a new word for…

This paper examines the acquisition of demonstratives (e.g., "that," "there") from a cross-linguistic perspective. Although demonstratives are often said to play a crucial role in L1 acquisition, there is little systematic research on this topic. Using extensive corpus data of spontaneous child speech, the paper investigates…

Data from elicited language tasks can add to the literature on the development of the complex syntax structures of embedded complement clauses in typically developing children. In the current study, preschool-age children (n = 27) participated in two elicited language tasks focusing on three types of embedded complement clauses: infinitival…

While semantic and syntactic properties of verb meaning can impact the success of verb learning at a single age, developmental changes in how these factors influence acquisition are largely unexplored. We ask whether the impact of syntactic and semantic properties on verb vocabulary development varies with age and language ability for toddlers…

Purpose: Children come to understand many words by the end of their 1st year of life, and yet, generally by 12 months, only a few words are said. In this study, we investigated which linguistic factors contribute to this comprehension-expression gap the most. Specifically, we asked the following: Are phonological neighborhood density, semantic…

Purpose: This study reexamines the claim that difficulty forming memories of words comprising uncommon sound sequences (i.e., low phonological neighborhood density words) is a determinant of delayed expressive vocabulary development (e.g., Stokes, 2014). Method: We modeled communicative development inventory data from (N = 442) 18-month-old…

Purpose: The objective of this study was to compare vocabulary size and composition in 2-year-olds learning Polish or English as measured by the Language Development Survey (LDS; Rescorla, 1989). Method: Participants were 199 Polish toddlers (M = 24.14 months, SD = 0.35) and 422 U.S. toddlers (M = 24.69 months, SD = 0.78). Results: Test-retest…

High rates of error and variability in early word production may signal speech sound disorder. However, there is little consensus regarding the degree of error and variability that may be expected in the typical range. Relatedly, while variables including child age, word frequency and word phonological neighbourhood density are associated with…

Vocabulary input frequency influences age of acquisition, and is also an essential control for investigating the influence of other factors. We propose a new method of frequency estimation, self-report. 918 Danish-speaking parents of 12-36-month-old children estimated their frequency of use of 725 words. Self-report was substantially correlated…

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…

Child-directed speech (CDS), which can help children learn new words, has been rigorously studied among infants and parents in home settings. Yet, far less is known about the CDS that teachers use in classrooms with toddlers and children's responses, an important question because many toddlers, particularly in high-need communities, attend…

The syntactic structure of sentences in which a new word appears may provide listeners with cues to that new word's form class. In English, for example, a noun tends to follow a determiner ("a"/"an"/"the"), while a verb precedes the morphological inflection [ing]. The presence of these markers may assist children in…

This cross-sectional study investigated the use of four verbal indices of social knowledge (personal pronouns, verb conjugations, people words and mental state language) and their concurrent relations in a sample of 287 Italian-speaking children between 18 and 36 months. Results showed that the production of all indices increased with age. Mental…

This article aims to investigate how Dutch children may eventually converge on a targetlike distribution of "hoeven" 'need,' a modal verbal NPI (Negative Polarity Item), based on its appearance in the scope of merely some but not all of its possible licensers in the language input (i.e., the induction problem). Imitation performance was…

This dissertation examined the role of maternal input in word order acquisition of Mandarin-speaking children from the one-word to multi-word stages. Four questions about the role of maternal input were addressed: frequency effects, age-related changes, utterance type effects, and verb diversity effects. Predictions for each question were made…