The current study examined how mothers' production of four types of internal state words at multiple ages across the second year in a free play context was related to their infants' acquisition of those words. Twenty-nine mother-infant dyads were videotaped for 18 minutes during free play when infants were 13 and 17 months old. Mothers' total and…

The present study examined the dyadic nature of fathers' and mothers' reported frequency of storybook reading by testing (1) the longitudinal association in parents' frequency of storybook reading when their children were 10.47 months old and 52.95 months old, (2) the interdependence between both parents' reported frequency of storybook reading,…

During the second year of life, children acquire words and expand their receptive and expressive vocabularies at a rapid pace. At this age, toddlers' phonological abilities are also developing rapidly. The current study investigated the effect of phonological complexity of words on the order in which they are acquired, receptively and…

It is well established that deictic gestures, especially pointing, play an important role in children's language development. However, recent evidence suggests that other types of deictic gestures, specifically show and give gestures, emerge before pointing and are associated with later pointing. In the present study, we examined the development…

In 2 cross-lagged, longitudinal studies we contrasted parental talk about want in a single context versus multiple contexts. Study 1 examined thirty-two 2 year olds, with mothers describing pictures to children. Mothers could use want in zero, one, or multiple contexts. Children whose mothers used want in multiple contexts experienced a…

The expressive lexical skills of 53 Polish bilinguals aged 24-36 months living in the UK and Ireland were assessed using Polish and British English adaptations of the MacArthur-Bates Communicative Development Inventories. Polish vocabulary scores were compared to those of 53 Polish monolinguals matched for age, gender and parental education. The…

This study explored individual variability in the bilingual vocabularies of 65 Maltese children aged 23-27 months (N = 33) and 30-34 months (N = 32). Most of the participants' direct input consisted of Maltese sentences embedding English words. Bilingualism was present at the societal level. Word production was measured through parental report,…

A revised form of MacArthur-Bates Communicative Development Inventory III (SCDI-III) was presented designed for Swedish speaking children aged 2 years 6 months-4 years 0 months with the objective to give a proxy measure of their language competence. The instrument contains a vocabulary checklist with 100 words, mainly predicates, from four areas;…

Purpose: This 2-phase study aims to extend research on parent report measures of children's productive vocabulary by investigating the development (n = 38) of the Spanish Vocabulary Extension and validity (n = 194) of the 100-item Spanish and English MacArthur-Bates Communicative Development Inventories Toddler Short Forms and Upward Extension…

Purpose: The goals of this study were to quantify longitudinal expectations for verb lexicon growth and to determine whether verb lexicon measures were better predictors of later grammatical outcomes than noun lexicon measures. Method: Longitudinal parent-report measures from the MacArthur-Bates Communicative Development Inventory (Fenson et al.,…

This study assessed the status of te reo Maori, the indigenous language of New Zealand, in the context of New Zealand English. From a broadly representative sample of 6327 two-year-olds ("Growing Up in New Zealand"), 6090 mothers (96%) reported their children understood English, and 763 mothers (12%) reported their children understood…

For more than 20 years, the MacArthur-Bates Communicative Development Inventory (CDI) and its adaptations for languages other than English have been used as reliable measures of infants' and toddlers' early receptive and productive vocabulary size. This article introduces the OZI, the Australian English adaptation of the MacArthur-Bates CDI, now…

Measuring individual differences in children's emerging language abilities is important to researchers and clinicians alike. The 2 most widely used methods for assessing children's vocabulary both have limitations: Experimenter-administered tests are time-consuming and expensive, and parent questionnaires have only been designed for children up to…

Young children who hear more child-directed speech (CDS) tend to have larger vocabularies later in childhood, but the specific characteristics of CDS underlying this link are currently underspecified. The present study sought to elucidate how the structure of language input boosts learning by investigating whether repetition of object labels in…

Recent studies demonstrate that emerging literacy depends on earlier language achievement. Importantly, most extant work focuses on "parent-reported production" prior to 30 months of age. Of interest is whether and how "directly assessed vocabulary comprehension" in the 2nd year of life supports vocabulary and kindergarten…