On Theme System and Textual Function

Guided by Halliday's and Thompson's theories of the Systemic-Functional Grammar,the paper studies English theme-rheme and its textual function according to the diagram of English thematic system that is taken from Introducting Functional Grammar(Thompson,2004).According to thematic theory,a clause is comprised of theme and rheme,the former being the first constituent of the clause and the latter being all the rest of the clause.Theme is the topic and is developed by rheme-the information body.Theme can be classified into marked theme,unmarked theme,enhanced theme in terms of its status and into simple theme and multiple theme according to its composition.Thematic progression between sentences,which mainly includes such patterns as TP with a continuous theme,TP with the same rheme,the simple linear TP pattern and the overlapped TP pattern,makes a text and the proper thematic-progression makes the text cohesive and coherent.