Development of noun phrase complexity in the writing of English for Academic Purposes students

•Noun modification varied with proficiency level.•Less proficient students relied on attributive adjectives as premodifiers.•More proficient students used more noun premodifiers and prepositional phrases.•The writing of the more proficient group was similar to published norms.•Classroom focus on noun–noun phrases and prepositional phrases is recommended.

Compared to conversation or other written registers, written academic prose favours heavy nominal groups, in which the head noun is typically accompanied by premodifiers such as adjectives or nouns, and/or by postmodifiers such as prepositional phrases. Focussing specifically on the noun phrase, this article uses the hypothesised developmental progression index suggested by Biber, Gray, and Poonpon (2011) to consider academic writing produced by two groups of graduate L2 writers. The first group was preparing for graduate study, and the second was already enrolled for graduate study. Noun phrases in our two sets of data were identified and pre-and postmodifiers were manually coded. Findings confirm the proposed developmental index in the sense that the less proficient group relied heavily on attributive adjectives, a modifier hypothesised as being acquired early. In addition, use of noun modifiers by the more proficient group was much closer to published frequencies for academic prose than was use by the less proficient group. Based on our findings, we make suggestions for applications in the EAP classroom.