Recall from my previous posts that certain words (we will call predicates) require additional material to complete their message. I used the examples of ate and the. Ate requires at least two additional pieces of material to be complete. That is, someone ate something. And, the requires at least one additional piece of material, the what?
So, the argument behind this hypothesis is that all verbs have specific thematic, or semantic roles that must be assigned to their arguments in a sentence. Let’s look at a new example, the verb "drive." Drive must have a subject to which it will assign the role of agent as in, “John drives.” This agent role is an active one. John is actively responsible for the driving of some vehicle. So drive needs at least one additional piece of material in order to convey a complete message. When a verb has only one “role” to assign we call these intransitive verbs.
When a verb can assign more than one role, as in, “John drives the car” we call these transitive verbs. In the second sentence we can see that drive assigns two thematic roles, one to the subject, “John,” and the other to the object, “the car.” Since the subject here is playing an active role we already determined that “John” receives the role of agent. However, “the car” (the object of the sentence) receives the thematic role of theme. A theme is the element which undergoes physical movement because of the verb. Therefore, with verbs such as "fell" or "disappeared," which only require one thematic role to be assigned, this role would be a theme since “to fall” or “to disappear” happens to someone and is not the result of the subject actively causing a change.
Other verbs can assign more than two thematic roles. These verbs are referred to as ditransitives. Gave is an example of such a verb: “I gave the book to my son.” In this sentence, “I” is the agent, “the book” is the theme, and “my son” is assigned the role of the goal.
Can you determine the thematic roles for this sentence:
When did she place the order of supplies for your department?