Transcript for:
Understanding Thematic Roles in Semantics

hello and welcome back to our semantics a lecture series if you may recall in our previous lectures we discussed the levels of semantic analysis who suggested that there were three levels the word level the sentence level and the utterance level in our previous lectures we discussed the word level now we begin with the sentence level under the sentence level we're going to discuss genetic rules and the difference between ambiguity and vagueness stay tuned alright so in this lecture we're going to discuss somatic roles or precisely we can call them semantic thematic roles for more information about genetic roles you can refer to John I Said's semantics specifically chapter six so what our theme somatic roles well if you have some basic knowledge of syntax you know that within a sentence every phrase serve some constituent part of the sentence so take for example John kicked the ball now were to think of basic syntax John would be the subject kicked would be the verb and the ball would be the object now that is syntactically speaking what a semantics have to say about this semantics also gives each constituent part a role that a plays so for example John in this sentence is the agent of the action of kicking the ball is the theme of the action of kicking now why is this necessary in the first place well here's why let's flip the sentence around and make it a passive sentence a ball is kicked by John notice how the ball serves as an object in this sentence but in this sentence it functions as a subject I don't see what semantics has to say in this sentence it serves as a theme because it is the entity undergo the effects of the action in this sentence as well the ball still remains as the theme because it still is the thing affected by the action so understanding these more stable semantic relations can also help to shed some light on how syntax works and how meaning works in general so let's begin by identifying some basic thematic roles an agent is the initiator of some action and is also capable of acting with volition volition means kind of like free and conscious will and the sentence John kicked the ball John serves as the agent because John is the one that initiated or started the action of kicking and John is an animates agent capable of making a decision to undertake or to start an action that's what we mean by capable of acting with volition if we were to say the raw fell on the boy the rock here will not be an agent because the rock is missing two main things it cannot be the initiator of an act because it's inanimate and also cannot act with coalition because it's also inanimate so that wraps up the agent the second theme attak role is the patient the patient is the entity undergoing the effects of some action and and often undergoing some change in States for example John pruned the trees so the action here is pruned John of course is the agent we should know that by now and the trees is the entity that is undergoing the effects of the action or pruning and not only that but it undergoes a change in state so the trees were one way and now they are another way due to the action of prune so we call this a patient the theme is the entity that is moved by the action or whose location is described Mary threw the ball again we should know by now that Mary is the agent that was the action now the ball is a theme here because when he throw a ball the ball usually moves from one place to another so a theme is the entity which is moved by the action or whose location is described so when we say for example Mary hid the ball under the table the ball here is also a theme because its location is described which is under the table so it's very important to keep in mind the difference between theme on the one hand and patient on the other a thematic role kind of similar to the agent is the experiencer the experiencer is the entity which is aware of the action or state described by the predicate but which is not in control of the action or state so if you really want to understand the experiencer role try to find out what the difference is between the verb look and see here's an example John looked at the moon John saw the moon and John looked at the moon John is an agent because John is the initiator of the action of looking and John undertook this action with volition but in John saw the moon John probably never intended to see the moon and probably didn't do it on purpose he just saw the moon and so John did not do this action of seeing on purpose and probably did not have any free will or choice in seeing or not seeing the moon and so to differentiate this case from the case of John here it's an agent we call this case an experiencer so john is experiencing only he's kind of like in the back seat he's experiencing the beauty of the moon closely-related as something called the percept or the stimulus and this is the entity which is perceived or experienced by the experiencer so john saw the moon I should know by now that John here is an experiencer not an agent because you have to pay attention to the action here the action here is saw okay or see you don't see things on purpose you look at things on purpose and so John is an experiencer the thing being experienced is called the percept or the stimulus Mary feared the dark some Mary here is experiencing fear now what caused this fear what is the what is the source or the stimulus of Mary feeling afraid it was a dark and so the dark is a percept or stimulus now the next world we're going to talk about is the beneficiary beneficiary is the entity for whose benefit action was performed so John bought Mary a car so let's begin since buying is something you have to be very conscious about when doing John is an agent bought is the action a car could be seen as either a theme or as a patient it really depends on whether you think the cars being moved from say the dealership to Mary or if the cars being changed in its States as being for example unsold to being sold this is actually one of the problems of thematic roles which we'll discuss later on but now who's this car bought for this cars bought of course for Mary she's the one that benefited from this deal so she is the beneficiary all right closely related to the benefit Shriya is something called the recipient now the recipient is a subtype of an automatic roll we're gonna discuss in a minute called the gold involved and actions describing changes of possession example john sold the car to Mary so the Mary here is the recipients of the car notice that this stays the same even if we change the sentence up a bit so John sold Mary the car Mary is still the recipient now let's talk about the goal the goal is the entity towards which something moves and this movement can either be literally or metaphorically so they can say John walked through school John is the agent walked as the action and the destination now or the goal of John's trip or his walking action is to get to the school so the school is the goal now that's a bit different from our next one called location now the location is a place where something is situated or takes place john hung the painting on the wall on the wall is a location described in where the painting is situated john saw the man at the library at the library describes where the action took place so it's also a location closely related to the goal is the source so this is the entity from which recall that the goal was to which something moves and this again can either be literally or metaphorically recall our example sentence from goal John walked to school simply changing this to John walk from school makes school become the source this is a place from where John cane you can actually pull both in the same sentence John home from school so the source is school now where was John heading in his walking action the goal was of course to get home we can also talk about another de Matic role called the instrument the instrument is the means by which an action is performed or something comes about John hit Bob with a stick how did this hitting action take place it happened by using an instrument which was the stick and that sums up all the thematic roles we're going to talk about in this class thanks for watching have a good day you [Music]