Studies have generally found that children starting as young as age of 2 1/2 begin to produce classifiers and reach adult understanding at the age of 6 of 7 (e.g., Chien, Lust and Chiang, 2003;Erbaugh, 1986).
using the word extension task, we tested four groups of children between the ages of three and six, and compared their performance to the results obtained from adults in Experiment 2.