This study investigates whether L2 learners (L2ers) use the same mechanisms as those of native English speakers (NSs) for processing regular and irregular past tense forms. Intermediate-to-advanced Persian-English L2ers and NSs participated in two online experiments using Speeded Grammaticality Judgment tasks. Experiment 1 examined regular and irregular past tense forms and Experiment 2 the effect of frequency on regular past tense forms. The results of both the accuracy and reaction time data show a pattern of convergence between NSs and L2ers. Particularly, the accuracy data provide new evidence showing that L2ers converge on NSs in showing distinct processes for regular and irregular tense forms. Additionally, both groups similarly showed an anti-frequency effect for regular verbs, i.e., the frequency increased accuracy rates for low-frequency regular verbs in comparison to high-frequency ones. It is concluded that L2ers use mechanisms similar to those of NSs for processing regular and irregular past tense forms.