Longitudinal Profiling of Chinese EFL Learners’ Lexical Frequency in Writing

This study aims to observe how EFL learners’ vocabulary develops across different frequency levels synchronically and across four semesters diachronically. To do so, it analyzes 299 Chinese EFL learners’ compositions using the Lexical Frequency Profile (LFP) method, involving as many as 20 different frequency levels of words. The study found that, synchronically, the percentage of words decreases exponentially as their frequency level declines within the first few levels, but fluctuates among the remaining levels. This pattern indicates that the participants’ vocabulary growth generally shifts from the highest frequency level to the lowest, following Zipf’s law, though not completely. Notably, the first few frequency levels combined account for about 95% of the composition: the first 1,000 words show the largest percentage, the second and third levels decrease exponentially, and the rest of the frequency levels contribute insignificantly. Diachronically, the first 1,000 words develop solidly and significantly, contrary to the second and third 1,000-word levels, thereby negating the traditional beyond 2,000-word boundary.