This paper reports a study on a Chinese English major＇s argumentative English writings focusing on the development of her thinking capacities and factors that facilitate or constrain such development. The data came from three sources： her essays, reflective journals, and my semi-structured interviews with her. Major findings can be summed up as follows： 1） at the initial stage, the participant was weak in rational thinking; 2） as she had more writing practice, she made progress in ideas and organization of ideas but not in expression of ideas; and 3） factors facilitating or constraining her development primarily include language input, cultural identification, teacher feedback and motivation.
In semantics, epistemic modality expresses writers＇ commitment to their propositions. In pragmatics, epistemic modality performs interpersonal functions. To date, its politeness and negotiative functions have been studied, but its constructive function seems to have failed to attract researchers＇ attention. Put simply, epistemic modal variants can be used to construct social reality, including writers＇ identity, writer-reader relations and the corresponding discourse community in which writers and readers live. The purpose of this paper is to provide a more complete picture of the interpersonal functions of epistemic modality and to raise Chinese learners＇ awareness of the importance of using such words appropriately.
