Previous research on visual word recognition has provided a fragmented view regarding the emergence and interaction of form and meaning in morphological processes. We aim to elucidate these temporal dynamics in an EEG experiment employing a lexical decision paradigm, focusing on oscillatory dynamics and ERPs during the visual recognition of Korean verbs. Considering the inherent polymorphemic nature of Korean verbs, we manipulated verb inflection types (base, regular, and irregular) to investigate whether the two inflected forms undergo the single processing system in a continuous manner or dissociative mechanisms in a categorical way. More importantly, by manipulating the semantic ambiguity of verb stems, we aimed to disentangle the interaction between form and meaning. EEG results revealed a graded effect of verb regularity in the N400 latency range, followed by an attenuated P600 amplitude and reductions in theta, alpha, and beta oscillations for regular inflections in the late time window. The current data provide neural evidence supporting single-system theories and the connectionist framework while challenging dual-mechanism accounts of inflectional morphology. Interestingly, not only an early semantic influence in the N250 time window but also a critical interaction of form and meaning was observed in the late time windows. Specifically, irregular inflection demonstrated alpha and theta reductions for homonyms in both early and late time windows, while regular inflection exhibited the opposite effect solely in the late time window. These findings are consistent with the single-system theory and form-with-meaning accounts, suggesting a differential reliance on the semantic information of regular and irregular inflections.