To begin with, no fixed definition is stated due to the overlapping and interference of naming and origin. For instance, a thematic role is defined as a term used in syntax and semantics to indicate the thematic relations that link a “predicate” to its “argument” in the description of a situation. Therefore, in the sentence (1) Tom broke the pencil the entities are connected by the action described by the verb, i.e. Tom as the agent; and the pencil as the theme. It has been suggested that these roles may be subsumed into two main types: the macro-roles of actor and undergoer, or, in an alternative terminology, the proto-roles of agent and patient. These roles have been important in the establishment of semantic classes of verbs.