What is happened may not be what appears to be happening: a corpus study of ‘passive’ unaccusatives in L2 English
Second Language (L2) researchers have been studying ‘passive’ unaccusative errors such as What was happened?, but have not yet reached a consensus about the ultimate cause of this unique interlanguage structure. This article critically reviews five major accounts proposed in the literature, namely: • transfer of a compound tense/aspect structure in the learner's first language (L1); • overgeneralization of adjectival passive formation in English; • nontarget lexical causativization; • identification of the passive morphosyntax with the lack of a logical subject; and • nontarget overt marking of syntactic NP movement. By analysing each account in terms of its ramifications in light of the data already available in the literature and additional data from a large corpus of nonnative English, I demonstrate that the most plausible account of the ‘passive’ unaccusative structure is to regard it as an overt marker of NP movement, an overgeneralization of the passive morphosyntax of the target English.