The ten papers in this volume focus on Subject and Theme. Theme began its life as a semantic notion in the work of Vile?m Mathesius, while Subject has traditionally been seen as just a syntactic entity. More recently two related perspectives on these concepts have attracted linguists' attention: the formal criteria for their recognition and the relations between the two concepts. Using the systemic functional model as their point of departure, the papers in the present volume consider the two notions in a wider context by relating them to the interpersonal and textual metafunctions of language.