Three- and four-year-olds (N = 144) were introduced to novel labels by an English speaker and a foreign speaker (of Nordish, a made-up language), and were asked to endorse one of the speaker's labels. Monolingual English-speaking children were compared to bilingual children and English-speaking children who were regularly exposed to a language other than English. All children tended to endorse the English speaker's labels when asked ‘What do you call this?’, but when asked ‘What do you call this in Nordish?’, children with exposure to a second language were more likely to endorse the foreign label than monolingual and bilingual children. The findings suggest that, at this age, exposure to, but not necessarily immersion in, more than one language may promote the ability to learn foreign words from a foreign speaker.

Using the Multiple Indicator Cluster Survey, language comprehension and production were compared in a sample of 101,250 children aged 2 ; 00 to 9 ; 11 and a focus subsample of 38,845 children aged 2 ; 00 to 4 ; 11 from sixteen under-researched developing nations. In the whole sample, comprehension slightly exceeded production; correlations between comprehension and production by country were positive and significant, but varied in size, and the average correlation was positive, significant, and small to medium. Mean comprehension and production varied with child age, reaching an asymptote at 5 ; 00, and correlations between comprehension and production by age were positive, significant, and similar at each age. In the focus subsample, comprehension exceeded production; correlations between comprehension and production by country were positive and significant, but varied in size, and the average correlation was positive, significant, and medium in size. Children in countries with lower standards of living were less likely to demonstrate basic language comprehension or production.

Considerable research has demonstrated that English-speaking children extend nouns on the basis of shape. Here we asked whether the development of this bias is influenced by the structure of a child's primary language. We tested English- and Spanish-speaking children between the ages of 1 ; 10 and 3 ; 4 in a novel noun generalization task. Results showed that English learners demonstrated a robust shape-bias, whereas Spanish learners did not. Further, English-speaking children produced more shape-based nouns outside the laboratory than Spanish-speaking children, despite similar productive vocabulary sizes. We interpret the results as evidence that attentional biases arise from the specifics of the language environment.

Investigations into early vocabulary development, including the timing of the acquisition of nouns, verbs and closed-class words, have produced conflicting results, both within and across languages. Studying vocabulary development in Irish can contribute to this area, as it has potentially informative features such as a VSO word order, and semantically rich prepositions. This study used a parent report adapted for Irish, to measure vocabulary development longitudinally for children aged between 1 ; 04 and 3 ; 04. The findings indicated that the children learned closed-class words at relatively smaller vocabulary sizes compared to children acquiring other languages, and had a strong preference for nouns.