Number and Person features carry different linguistic information, which are associated with specific brain activities and neural substrates. Functional magnetic resonance imaging (fMRI) revealed a specific response to Number Violations in the pars opercularis (PO), whereas Number and Person Violations both activated the posterior superior temporal gyrus (pSTG), with larger effects for Number as compared to Person violations. In order to characterize the nature and time course of these effects we investigated them in event-related potentials (ERPs) by reanalyzing a previously published data set. Participants were 32 balanced Turkish-Persian bilinguals who had learned Persian at the age of seven when formally entering primary school. R-expressions and Pronouns in Persian sentences were used for testing the effects of Number and Person violations, respectively, across different syntactic conditions. At the behavioral level, the grammaticality effect was much larger for Number feature than for Person feature, clearly reflecting the Number’s cognitive strength and its processing saliency. At the ERP level, there were significant main effects of grammaticality and of feature in the P600 time window, but their interaction did not approach statistical significance. The performance results converge with our previous fMRI results indicating the special status of Number feature processing, while the ERP results are as yet inconclusive and require further examination.