Several hypotheses have been formulated to predict the pattern of performance on finite verbs by agrammatic speakers. The present study is focused on finite and nonfinite verbs in base-position. Three finite verb forms (third person singular in past and present tense and third person plural in present tense) and three nonfinite verb forms (infinitives in two different constructions and participles) were tested.The main results are that finite verbs are more difficult than nonfinite verbs, but both within the finite verbs and within the nonfinite verbs, the forms referring to the past (third person singular past tense and participle respectively) were more difficult than their counterparts referring to the present (third person singular present tense and infinitives). None of the hypotheses on verb forms can account for these results. Therefore, we suggest that an additional hypothesis is needed which expresses that agrammatic speakers have difficulty making reference to the past.