The use and development of academic vocabulary in second language writing: a longitudinal investigation

Recent years have seen the increasing use of vocabulary frequency lists such as 'the 1,000 most frequent words in English' to assess the difficulty of reading texts, as well as the development of learners' language. This paper reports on a longitudinal study of university essays in English, written every ten weeks under examination conditions, over a period of two years by 42 Arabic-speaking students.  The expectation was that students’ use of academic vocabulary would begin with those words used most frequently in academic English and, as their vocabulary developed, draw increasingly from less commonly-used words.  The evidence from this study of written output suggests that the frequency lists, which are based on academic usage by (near-)native users of English, may not be as applicable as thought for modelling the development of vocabulary use in learners of English as a second or foreign language.