The involvement of rule-based computation is the focus of the past tense debate. The present masked priming study contributed to the debate by investigating how Chinese EFL learners processed regular English past tense forms. The results show that, for the past tense forms of relatively high frequency, at the early stage of processing, the highly proficient group can make use of morphological rule to decompose regular past tense forms. The lower proficiency level group, however, cannot decompose past tense forms. It is suggested that surface form frequency of past tense inflections and foreign language proficiency are the two factors that affect the way complex words are processed. Our data supports the dual-route model of Declarative-Procedural memory in the past tense debate.
