This article reports on a case study that analyzed the use of evaluative language in one Chinese EFL student's argumentative writing in both English and Chinese. It focuses on the subsystem of "attitude" from appraisal theory. The study found similar patterns in the use of "appreciation" items but differences in "affect" and "judgement" between the student's English and Chinese essays. It proposes that understanding EFL/ESL students' use of evaluative language requires considering both linguistic and socio-cultural perspectives.