Lexical Development in L2 English Learners’ Speeches and Writings

In order to investigate how learners’ L2 vocabulary develop in speeches and writings, the current study analyzed a new learner corpus including speeches and writings of varied Asian learners of English. The analyses revealed that as learners’ L2 proficiency levels increased, lexical diversity decreased and then increased, lexical density remained unchanged, and lexical complexity steadily increased. Furthermore, lexical fundamentality increased and decreased in speeches and writings respectively, and the degree of noun orientation slightly decreased. It was also shown that learners’ spoken and written vocabularies developed largely in a different way. Additional statistical analysis revealed that learners’ L2 vocabulary use was influenced the least by L2 proficiency, and the most by L2 production mode, followed by nationality and L1.