A Study of a Variety of Elliptical and Marked Themes in English and Persian Physics Texts:Halliday’s Systemic Functional Grammar Perspective

In the present study, some sections of physics text written in Persian and English were studied based on Halliday’s systemic functional grammar. through a clause analysis, ten types of themes were identified and their frequency and percentage were determined. One of the results showed that 58% of corpus themes were simple, 42% were multiple, 81% were unmarked and 19% were marked. In this study different types of themes and their frequency in Persian and English were also compared. The results indicated that elliptical and marked themes were used more in Persian than in English. However, the differences among the other types were partial. Furthermore, theme variation and their frequency in book and article were examined. In the studied ‘books’ they were used more than the studied ‘article’.