Time reference in Indo-European languages is marked on the verb. With tensed verb forms, the speaker can refer to the past (wrote, has written), present (writes, is writing) or future (will write). Reference to the past through verb morphology has been shown to be particularly vulnerable in agrammatic aphasia and both agrammatic and non-brain-damaged individuals have longer RTs with verb forms referring to the past than with verb forms referring to the present (Faroqi-Shah & Dickey, 2009). It has been argued that these results are due to the discourse-linking nature of past tense (Bastiaanse et al., 2011). This article reports ERP and behavioral (reaction time and acceptability rating) data on the processing of time reference violations in which verb forms do not match a time frame previously set by an adverb (present adverb-past tense verb; past adverb-present tense verb). The results show that violation by a present tense verb yields a P600 time-locked to the verb. No such response is found for violation by a past tense verb. These ERP results are similar to ERP findings on locally bound and discourse-linked pronominal processing and when related to behavioral findings on identical violations, support the claim that in present tense processing co-reference is established with the speech time (local binding), while past tense processing involves co-reference with some other event time (discourse-linking). (Contains 7 figures and 3 tables.)