Non-nativelike outcome of naturalistic child L2 acquisition of Japanese: The case of noun-verb collocations

Many second language (L2) studies have shown that naturalistic L2 acquisition beginning from childhood leads to nativelike proficiency. The current study investigated whether the acquisition of such proficiency would be guaranteed, by examining a potential gap in the seemingly nativelike L2 proficiency of child L2 starters. At issue was the productive knowledge of noun-verb collocations by child L2 starters of Japanese (n = 74, age 13-18) whose age of arrival (AOA) was between 0 and 11 and whose length of residence (LOR) was between 5 and 18 years. The collocation test included only items that were easy for native speakers (NSs) (n = 162, age 13) agematched for the youngest L2 participants. About one-third of the L2 participants, including the earliest arrivals, scored below the NS range on the collocation test. The current study concludes that early L2 onset does not guarantee nativelike productive knowledge of collocations, even when the collocations in question are very easy for NSs. The study also discusses pedagogical implications for child L2 starters, who are generally believed to become nativelike with ease.