The Syntax of Event Structure

The Syntax of Event Structure James Pustejovsky

Overview • Another theory describing verb behavior • Behavior at the surface is related to some internal event structure • Works at one level of abstraction above traditional theories: generative versus exhaustive • Exhaustive: Build theory around a fixed set of primitive constructs (cause, become, etc) • Generative: Build theory around a fixed set of “generative devices” – rules for how constructs relate

Event Structure • Three parts • Event type • State, Process, Transition • Rules for event composition • Rules for mapping to lexical structure

Aspectual Types • State • Mary is sick. • Nothing changes during the sentence. • Process • Mary walked. • No bounds given • Event (Transition) • Accomplishment – has a logical culmination • Mary walked to the store • Achievement -- Like accomplishment, but no middle (point-like): • John died at 3pm • Bounded Process -- has a temporal constraint: • Mary walked for 30 minutes

Default Verb Behavior • In the previous slide, walk was used for three different aspectual types • Unmodified (by default), it refers to a process • Prepositional/Adverbial phrases can override its “process-like” property • Mary walked. (Process) • Mary walked to the store. (Transition)

Other Defaults • Build & Destroy – Accomplishment • Mary built a house • Culmination: the house is done • Mary destroyed the table • Culmination: the table is a pile of rubble • Can be overridden • Mary built houses for four years. (process) • Hmm… • Mary walked to the store for four years • Process to transition back to process?

Conveying Meaning • Verbs specify an opposition of terms • Rather than try to exhaustively define them, just compare to opposition. • Closed and not closed • At the store and not at the store • This forms part of the qualia structure of a word • Constitutive role • The relation between it and its constituent parts • Formal role • That which distinguishes it within a larger domain • Telic role • Its purpose and function • Example: Book -- Read • Agentive Role • Whatever brings it about • Example: Book – Write • The point of mentioning this: can use event structures to instantiate qualia structure, and qualia structure to organize event structures.

Notation • Works like production rules in a grammar • Capital letters are nonterminals • Lower case letters are terminals • E: Event. E  {S, P, T} • e: Event instance • P: Process • T: Transition • S: State

LCS’ versus LCS • Events bottom out in case-structure like predicates: act(x, y); at(x, y); etc • Unlike normal case structure, there is no fixed set of primitives – just make predicates up as needed by comparing to opposition.

Composition Rules: State S e • Examples • Be sick • Love • Know

Composition Rules: Process P e1 . . . en • Examples • Run • Push • Drag

Composition Rules: Transition T not E2 E1 • Examples • Give • Open • Build • Destroy

Examples S • The door is closed. • The door closed. • John closed the door. e closed(the-door) T P S not closed(the-door) closed(the-door) T P S act(john, the-door) & not closed(the-door) closed(the-door)

Accomplishment versus Achievement Revisited • New definitions • If a verb introduces an opposition and mentions the cause (agent), it refers to an accomplishment • When the agent is not referenced, the verb is an achievement T S P Q(y) act(x, y) & not Q(y) T S P Q(y) not Q(y)

Smoke & Mirrors • This seems to have little to do with the previous “point-like” versus continuous definition of achievement and accomplishment. Apparent counterexamples include: • Mary arrived at the party. • John won the race. • But agency here is contributed by pragmatics rather than the nature of the verb: • The package arrived at the office. • Mary won the lottery. • Note that intentional adverbials (deliberately) can’t modify predicates such as win and die.

Event Composition • Rules exist for determining which compositions work and which don’t • Three things to look at • Adverbials • Prepositional phrase attachment • Resultative construction • Event type for a sentence may not be the event type for the main verb

Durative Adverbials • Processes can take durative adverbials • Mary ran for an hour • Transitions cannot • *Mary built a chair for an hour

Frame Adverbials • Processes cannot take frame adverbials • *Mary ran in an hour • Transitions can • Mary built a chair in an hour

Prepositional Phrase Attachment • Prepositional phrases can shift the event type of a phrase: • Mary ran. (process) • Mary ran to the store. (transition) • The PP adds a state to the process, turning it into a transition • Hey, neat, the frame adverbial thing holds: • *Mary ran in an hour • Mary ran to the store in an hour

Resultative Constructions • Similar type shifting can occur • Mary hammered the metal. (process) • Mary hammered the metal flat. (transition) • *Mary hammered the metal in an hour. • Mary hammered the metal flat in an hour.

More with Adverbs • Wide versus Narrow scope: • Lisa rudely departed. • It was rude that Lisa departed. (adverb modifies her intention) • Lisa departed in a rude manner. (adverb modifies how she departed) • There are as many interpretations for an adverbial as there are distinct predicates in the event structure. • John almost built a house. • John was going to build a house but decided against it. • John attempted to build a house but never completed it. • John almost ran. • John was going to run but decided against it.

Achievement and Accomplishment Re-Revisited • Recall that achievements are accomplishments without mention of cause • Therefore, there should be two interpretations for accomplishments modified by adverbs • One for the intent • One for the actual transition • John almost built a house. • …and one for achievements • The actual transition • John almost died.

From Event Structure to Argument Structure • A) The semantic participant involved in a predicate opposition is mapped onto the internal argument position of the lexical structure. (object) T P S not Q(y) Q(y) Here, the y becomes the argument of the verb: V(y)

From Event Structure to Argument Structure • B) The agentive participant in the initial subevent of the event structure is mapped onto the external argument position of the lexical structure (subject) T P S act(x, y) & not Q(y) Q(y) Here, the x becomes the first argument of the verb: V(x*, y)

From Event Structure to Argument Structure • C) If the predicate opposition involves a relation, then both the participants are mapped onto internal argument positions of the argument structure. Otherwise, relational arguments are mapped directly as expressed at event structure • Give me your candy  act(you) & give(me, candy)

From Event Structure to Argument Structure • D) Any participant in the initial event not expressed by A) or B) is mapped onto the external argument position • E) Each subevent must be associated with at least one argument position at lexical structure.

The Syntax of Event Structure