Proposed that the verb is stored in long-term memory as a set of semantic features. 56 undergraduates recalled sentences which contained 1 of 8 verb forms. The verbs were either past or present, progressive or nonprogressive, and perfect or nonperfect. In recall, verbs underwent semantic simplification. Perfect verbs were often recalled as nonperfect, and progressive as nonprogressive; however, present perfect verbs were often recalled as simple past, and present perfect progressive as past progressive. Each change entails the loss of 1 semantic feature, i.e., a simplification in the interpretation of the verb. The net result was a bias toward recalling past, nonperfect, and nonprogressive verbs. The errors in memory, it was argued, can be accounted for either by a theory of semantic memory or by a theory of syntactic memory with a basic reformulation of the verb's syntactic rules. (17 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved)