The Productive Vocabulary Size of Second Language Learners upon Entry into Higher Education

Extensive vocabulary acquisition is a cornerstone of second language (L2) proficiency, directly influencing both receptive and productive language skills. However, research on the productive vocabulary size of L2 learners transitioning to higher education, particularly their mastery of high-frequency words, remains limited. This study investigated the productive Hebrew vocabulary size and frequency distribution of Arabic-speaking learners entering higher education programs where Hebrew is the primary language of instruction. The research employed a corpus-driven approach, analyzing 156 Hebrew-language argumentative essays (18,054 orthographic words) written by native Arabic-speaking students during a college entrance examination. Automated tools were used to add contextual vocalization and disambiguate homographs, followed by manual annotation mapping each word to its corresponding lemma. The identified lemmas were then compared to established written and spoken Hebrew frequency lists. This process aimed to chart the vocabulary profile of the research population. The study determined that learners had a productive vocabulary size of approximately 1,000 lemmas, despite completing over 1,000 hours of formal L2 instruction. A comparison with established written and spoken Hebrew frequency lists indicated that 50% of the identified lemmas fell within the 1,000 most frequent Hebrew lemmas. Additionally, the learners exhibited a typical vocabulary profile, employing more lemmas from the 1k frequency band (the 1,000 most frequent words) than from the 2k frequency band (words ranked 1,001–2,000). Similarly, their use of lemmas from the 2k band exceeded that of the 3k band (words ranked 2,001–3,000), which in turn surpassed their use of lemmas from the 4k band (words ranked 3,001–4,000). These findings highlight the learners’ significant reliance on high-frequency vocabulary in L2 writing, emphasizing the need for targeted academic vocabulary instruction as they transition to higher education.