Sources and Instruments

(Non-linguists: thematic role in syntax/semantics is the relationship of entities in a sentence to each other based on the action described. For example, in "Tony bought a car," Tony is the agent and a car is the patient; Tony is doing the buying, and a car is being bought. This is different than a subject-object relationship as the sentence can be rephrased "The car was bought by Tony," and the thematic roles don't change even though the grammatical roles do. However, as will be shown here, these roles are not always so obvious.)

In the sentence "Jay learned French from Kim," what is the thematic role of Professor Kim? To potential answers are immediately apparent: either Kim is the source, in which case French (or knowledge thereof) can be said to come from her and go to Jay, or she is instrumental, in which case Kim can be seen as a conduit by which the French language can be obtained. One problem here is that the patient in this sentence (French) is a non-material entity, so it cannot strictly have a source from which it moves to Jay (the beneficiary, or possibly agent); another issue is whether Kim is being used in the strictest sense to learn this French.

I would be inclined to argue that Kim is an instrument more than a source here, since the sentence describes an action on French that does not strictly affect it - and certainly does not move it - and Kim's part in the action is to assist Jay in the action (a source implies more passivity).

Another interesting thematic thought: in the sentence "Peanut-butter jelly with a baseball bat," is the baseball bat's role instrumental or comitative? Discuss.