Passive Participles and Theta Role

[Kiltman67]

I'm desperately studying for a Syntax exam which is all making little sense to me (Psychologist in a Psycholinguistics Masters getting hit over the head with the second half of the portamenteu!). One thing in my notes that's puzzling me is, in a discussion of passitivization, that making a passive participle out of a verb supresses the external theta-role of the verb.

I don't understand this, I thought the theta-role dictated arguments like agent, theme etc., so how can this be surpressed? Surely if it's the same verb then it has the same arguments? Unless it's a particularly overcomplicated way of saying that since a passive participle isn't a verb it won't have arguments anymore.

[Mister Micawber]

.
The agent disappears or is subordinated in passive voice. Compare:

My work tires me.
I am tired (by my work).
.
_________________
Native English teacher at Mister Micawber's

[Jamie (K)]

The verb dictates its own theta roles. The external theta role is usually the agent or theme (when the theme is the subject of the verb in the non-passive sentence). As Mister Micawber writes, your statement means that the agent disappears in the passive sentence. Actually it doesn't really disappear, but it is what would be called in linguistics "covert", as if it were present but hiding.

So if someone says, "Mistakes were made," the agent does not really disappear, and it is covertly still in the sentence, because a person would be likely to ask, "Well, who made those mistakes?" So the agent is still there, but it's not overt.

Not everything that seems to "disappear" in a sentence is really gone. Sometimes it is just covert, suppressed, or in colloquial terms we can say it "hides", but it's still there.