Noun and Verb (Re)learning: A Comparative Perspective on Acquisition and Post-Stroke Aphasia

Abstract

Nouns and verbs are fundamental building blocks of language, yet they exhibit important asymmetries. In language acquisition, nouns typically enter young children's lexicon earlier and are acquired more easily, while verbs are learned later and with greater difficulty. The mechanisms supporting the acquisition of these two categories also differ: nouns are often learned through observational and social contexts, whereas verb learning heavily relies on the nouns that accompany them. This noun-verb asymmetry evident in language learning is paralleled in language relearning among individuals with aphasia. Verbs are generally more vulnerable to impairment than nouns, and the recovery of verbs is shown to benefit most from treatments that target the nouns serving as their arguments. While previous research has separately addressed the noun-verb asymmetry in the contexts of both learning and relearning, there has been a lack of comparative discussion between these domains. This review article integrates findings from both areas, reinforcing the view that nouns and verbs differ significantly in their linguistic and psycholinguistic properties and neural representations—differences that underpin the disparities observed in their acquisition (learning) and recovery (relearning).