The present study explores the influence of different intervening test types and feedback have on English grammar acquisition in the immediate and long-term retention. Seventy-one college students were randomly assigned to a short-answer test group, a multiple-choice test group, and a control group. Three main instruments were utilized in the study: a background questionnaire, pre- and post-Grammar Learning Strategy questionnaires, and pre-, post-, and delayed grammar tests. The outcomes of the study indicate that both experimental groups had significantly higher grammar gains than the control group in terms of immediate retention, while a short-answer test group showed better retention than the control group in terms of long-term retention. In addition to testing effects, the two experimental groups reported a positive attitude with regards to memory-related, cognitive, and metacognitive grammar learning strategies. Based on the results, this study offers suggestions on how tests can be effectively implemented into L2 English grammar instruction.