Another take on the notion Subject
Linguistic theories typically have a static, competence-based view of the notion Subject. In this view speakers choose their Subjects freely from the relevant constituents of a clause, typically the arguments of the main predicate. However, when one looks at what speakers actually do, it becomes clear that the choice is determined to a high degree on the basis of the pragmatic and semantic features of the candidate constituents. Apart from roles such as Agency and Topicality, the major determining factor appears to be a possibly language specific mix of features such as person, animacy, and definiteness. A multifunctional approach to Subject choice seems to work even for English, a language which is thought to have grammaticalized Subject to a large extent.