Elicited imitation tests (EIT) are often used to measure the effects of a form?focused intervention on the development of L2 learners’ implicit grammatical knowledge, which is intuitive and retrieved without conscious awareness. This study investigated the relationship between an EIT focused on the English past tense and a set of other tests; it also examined whether the past-tense morpheme type, grammaticality of the verbs, their position in the stimulus utterances, and the explicitness of the test instructions influence learners’ imitation accuracy. Forty-four university-level students, all native speakers of Mandarin and enrolled in an English for academic purposes program in Canada, completed an EIT along with four other tests over two consecutive sessions. Results revealed that only the imitation of irregular verbs was significantly correlated with the other tests. In addition, the participants were more accurate in repeating the grammatical and correcting the ungrammatical regular verbs but neither the position of the verbs nor the type of instructions significantly influenced imitation. These findings suggest that several factors can influence learners’ performance and the knowledge that they draw upon during an EIT.