  Although significant progress has been made in developing methods for
Grammatical Error Correction (GEC), addressing word choice improvements has
been notably lacking and enhancing sentence expressivity by replacing phrases
with advanced expressions is an understudied aspect. In this paper, we focus on
this area and present our investigation into the task of incorporating the
usage of idiomatic expressions in student writing. To facilitate our study, we
curate extensive training sets and expert-annotated testing sets using
real-world data and evaluate various approaches and compare their performance
against human experts.
