2.2.1. Subject and object identification
Each argument is associated with a semantic role in relation to the verb. There is a close relation between the semantic role of a constituent and its syntactic function in the sentence. In a clause with an intransitive verb, the semantic role of the single argument is agent, experiencer or theme. The argument of an intransitive verb functions as the subject of the sentence. In an active clause with a transitive verb, the constituent with the semantic role agent or experiencer is typically the subject and theme is the object. An active clause with a ditransitive verb has three arguments. The semantic roles and the grammatical functions of the arguments are agent/subject, theme/object, recipient or source/indirect object.
The morphological type of the verb (plain, spatial, or agreement), the animacy of the verb’s arguments, and the information structure are the main factors that determine the positions of subjects and objects in the sentence.