Mystery of child word learning order

This study investigates cross-linguistic universality using the English and Spanish Lex2005 Communicative Development Inventories (CDI) database along with our Japanese CDI database. We define the word-comprehension and word-production days as those when 50% of the children comprehend and produce a word, respectively. The correlations between comprehension and comprehension-to-production days for the two languages were calculated category on category and word on word. These results confirmed strong correlations between word-comprehension days and word-comprehension-to-production periods as seen through both category-on-category and word-on-word comparisons. This suggests that there is cross-linguistic universality of word-acquisition periods for comprehension and comprehension-to-production.