7.6 Events and thematic roles

So far in this chapter, we have discussed how there are different types of meaning, and how there are different theories about how lexical meaning works in our minds. In this section, we begin to explore various linguistic phenomena that highlight our semantic competence as language users. The way to think about meaning like a linguist is to look for semantic patterns. Here are some questions we will answer in analysing linguistic meaning:

1. Why is this combination of words well-formed, and why is that combination of words ill-formed? What does this tell me about the lexical semantics of this word? What other words behave this way? (e.g., I drank the water sounds OK, but I drank the ice does not; this tells us that drink requires its object argument to be liquid)
2. What semantic categories are there in language? What semantic classes of verbs are there? What semantic classes of nouns are there? What semantic classes of adjectives are there?
3. What types of information is linguistic meaning generally sensitive to?
4. In what ways do different languages vary in their semantic parameters?

To make Question 2 easier to keep track of, the upcoming sections are organised by syntactic categories. This section (7.6) will focus on verbs, 7.7 will focus on nouns, and 7.8 and 7.9 will focus on adjectives.

Syntax throwback: Arguments and thematic roles

In the Syntax chapter (Chapter 6), we learned that some verbs are intransitive, some are transitive, and some are ditransitive. This concerns how many arguments the verb takes. (4), (5), and (6) show an example of an intransitive verb, a transitive verb, and a ditransitive verb, respectively. The predicate is bolded, and the arguments are underlined.

We tend to think of verbs when we think about predicates, but recall from 7.2 that nouns and adjectives can be used predicatively, too. In English, nouns and adjectives that are used predicatively follow the copula be.

Many predicates refer to some sort of event. Events are dynamic: something is happening. The sentences in (9)-(11) describe events.

Some predicates do not point to anything “happening”: what’s going on is much more stative (non-dynamic). (12)-(14) describe states.

You can tell events apart from states because an event can be an answer to the question “What happened?” while states generally cannot. This is exemplified in (15)-(16).

The umbrella term that includes both events and states is eventuality. Verbs seem to encode what kind of eventualities are involved in its meaning.

Recall also that participants in eventualities take on various roles, depending on what the predicate is. So this means that the lexical information of verbs don’t just specify the number of arguments that it takes; it also specifies what role these arguments have. These roles are called thematic roles. Here is a list of thematic roles that were introduced in the Syntax chapter.

• Agent: Agents are animate actors who do things on purpose.
• Causer: Usually inanimate (not alive), cause things to happen but without acting on purpose.
• Theme: The participant affected by the event, may be changed by the event.
• Instrument: The thing an agent uses to accomplish an action. (Often, but not necessarily, in a with PP)
• Location: The place where the event takes place.
• Experiencer: An animate participant that experiences a mental state, including perceptions (see, hear, etc.)
• Goal: The location or place that receives the theme.

Eventualities, entailments, and conjunction

What do thematic roles tell us about the meaning of verbs? Consider the following sentence.

There are several things that this sentence entails:

1. There was a lifting event;
2. The building was the theme of this event;
3. The spatula was the instrument of this event;
4. The chef was the agent of this event.

This entailment pattern is similar to entailments of sentences that are coordinated with the conjunction and:

(18) entails:

1. The big cat stole a treat;
2. The small cat meowed.

Based on this similarity, we can also analyse the lexical semantics of lift to also involve “and” (conjunction).  Putting all of the observations together, we can propose that the lexical semantics of lift specifies what participants it needs in the event, and that this is expressed conjunctively. Using variables (recall Section 7.3), we can express the meaning of lift like this (this kind of semantic representation that makes reference to events can be called event semantics):

Remember that variables are place holders. The idea is that each argument in the sentence in (13) fills in, or saturates, these argument positions represented by the variables. Let’s assume that the argument positions get saturated in the order we see them in (15): so x gets filled in first, then y, and then z. As a reminder, the syntactic structure of this sentence looks like the structure in Figure 7.12. Let’s see what happens when the meaning of lift combines with the meaning of the arguments in this sentence. Let’s assume that the egg means whatever specific egg we are referring to in the discourse, that the spatula is also a specific spatula, and that the chef is also a specific chef that has been mentioned in the discourse already.

As a first step, the verb combines with its object. When the verb merges with its object the egg, the meaning of the egg would go into the x. That produces the verb phrase lifted the egg, which would have a meaning like this:

This verb phrase then merges with the prepositional phrase with the spatula, and the meaning of the spatula will go into y:

Finally, the verb phrase lift the egg with the spatula merges with the subject DP the chef (we will ignore tense for simplicity). The meaning of the chef goes into z:

This gives us the full meaning of The chef lifted the egg with the spatula, and it gives us the entailment pattern we saw in (17), due to the conjunction that is a part of the lexical meaning of lift.

To summarise, one way to analyse what is happening with the thematic roles of arguments in sentences is to posit that the thematic roles are specified in the basic meaning of verbs.

Check your understanding

References

Kearns, K. (2011). Semantics. Basingstoke: Palgrave Macmillan.

Davidson, D. (1967). The logical form of action sentences. In N. Rescher, ed. The Logic of Decision and Action. Pittsburgh, PA; University of Pittsburgh Press. 81-120.