This study examined the effect of word class (nouns vs. verbs) on L2 pronunciation accuracyof Korean–English bilinguals. The participants were 192 adult immigrants whose age ofarrival (AOA) in the United States ranged from 6 to 23 years. Transcriptions of their productionsof English sentences indicated that they were more accurate in pronouncing verbs than nouns.Similarly, the results of a grammaticality judgment test revealed that they were more accurate indetecting incorrect formulations of verbs than nouns. These effects were significant in late L2learners (AOA 12–23). The results were interpreted to reflect the influence of the linguisticstructure of Korean (where the verb is more prominent than the noun) on learning English as anL2.