In the literature, L2 learners of English are reported to have problems accepting grammatical unaccusative sentences like the cup broke yesterday although they accept the passivized form like the cup was broken yesterday (e.g. Yip 1995; Ju 2000). They also produce ungrammatical sentences like “If the World War III is happened, . . .”. It has been suggested that these phenomena are universal in the development of L2 English because they occur in the English of L2 learners with different L1s (cf. Ju 2000). This paper presents an empirical study investigating whether these non-target phenomena also occur in L2 Chinese. It is found that English speakers of Chinese at different proficiency levels fully accept the NP-V unaccusative construction. Optionality is observed in English speakers’ non-target passivized unaccusative verbs of change of state, which are argued to be due to L1 transfer when English speakers incorrectly treat Chinese change-of-state verbs as causative. Overall, the results suggest that the overpassivization phenomenon should not be considered universal in the L2 acquisition of unaccusativity despite their prevalence in L2 English.