Whether Mandarin is a verb-friendly language for young word learners or not is a hotly debated issue. Researches on children's word learning were either naturalistic study or experimental study, and they were from cross-cultural perspective. This study tries to examine the noun/verb proportion in Mandarin infants, from a longitudinal perspective; it also examines how Mandarin infants understand their first nouns and verbs using both naturalistic study and experimental study. The results of this research are:
1） According to the results of CDI test, Mandarin infants of 18 month old could say more verbs than nouns significantly; while 24 month-olds could say more nouns than verbs significantly.
2） According to the results of CDI test, Mandarin infants’ verb/noun proportion was higher in 18 month old than in 24 month old. This means that the relative advantage of verb learning may be easier to show up in infants younger than 2 years old.
3） The total vocabulary of 18 month-olds was positively correlated with the Mean Length of Utterances(MLU) of 24 month-olds. The MLU of 24 month olds was positively correlated with the verbs of 18 month-olds.
4） Only 24 month-old could succeed in our IPLP study and showed “true” understanding to their familiar words. 14- and 18- month-olds watch the target side and non-target side randomly.
5） According to the results of IPLP study, the infants could understand nouns better than verbs. Both female and male infants understood nouns better than verbs, but females seemed to have stronger tendency to watch the object-same side in both noun and verb condition.
6） According to the results of parents’ reports, all the infants in 3 age groups could understand verbs as well as nouns, and they are quite familiar with those words. However, IPLP study results showed that these infants understood nouns better than verbs.
7） In IPLP study, less than 50% of the Mandarin infants watch the target side of verbs longer than the non-target side (action-same response). However, the AS responses appear more frequently in verb condition than in noun condition among 24-month-olds.