Together at Last: How Tense and Aspect Interact in Simulation Semantics

1. Together at Last:How Tense and Aspect Interact in Simulation Semantics ECG Theme Session ICLC03 University of La Rioja July 24, 2003

2. The Problem • Aspectual theorists have proposed revealing models of type shifts, both explicit and implicit: • Explicit type-shifting • Progressive: Process  State (e.g., She was singing) • Perfect: Event  State (e.g., The Eagle has landed) • Implicit type-shifting (coercion) • State  episode of stasis:She was depressed twice. • State  inchoative event: I liked her within a minute. • These models rely on an ontology of idealized situation types (process, state, event, etc.). • In this respect, they are incompatible with models of tense. ECG Theme Session ICLC03 University of La Rioja July 24, 2003

3. The Problem • Unlike aspect, tense lacks an ontology. • Tense is purely relational: there are no ‘tense-type entities’ corresponding to aspectual-type entities. • Tense relates speech time to reference time (R). • R is located relative to the encoded situation; it constrains inference potential. • Tense semantics are therefore based on a location metaphor: R is speaker/hearer location. • By contrast, aspectual semantics are based on an entity metaphor. • But tense and aspect are much more similar than the traditional models imply. ECG Theme Session ICLC03 University of La Rioja July 24, 2003

4. Tense-Aspect Interfaces • Tenses convey aspectual perspectives like ‘attention to endpoints’: • My ex-husband is/was Latvian. • I took a cab over. The driver was/?is Latvian. • Aspect determines ‘direction of inclusion’ for R: • State: Pat was in Cleveland in June. (state overflows R) • Event: Pat visited Cleveland in June. (event exhausted by R) • Tense and aspect jointly encode overlap/sequence: • I told them I had (had) more time on the meter. • Tenses select aspectual types, and as such are coercion triggers. a eu Margot s’est retournée. Henri avaitl’air heureux. ‘Marge turned around. Harry was (perf/imperf) happy.’ ECG Theme Session ICLC03 University of La Rioja July 24, 2003

5. Our Purpose • We will propose a simulation-based model of tense that is isomorphic to models of phasal aspect proposed by Narayanan 1997 and Chang, Gildea & Narayanan 2000. • This model will capture tense-aspect interfaces, in particular the role of tense in triggering aspectual type-shifts. • We will use this model to account for two traditionally mysterious kinds of semantic effects: • Habitual coercion: She took the bus to work that summer. • Present-tense coercion: She takes the bus to work. • We will model these type shifts by assuming x-schemas for tense that are combinable with aspectual x-schemas. • Tense x-schemas will be known as sampling sets. ECG Theme Session ICLC03 University of La Rioja July 24, 2003

6. Coercion by Tense: Habituals • Habitual predications count as state predications: • Extensibility • She smoked back then and I think she still does. • *She enlisted in 1985 and I think she still does. • Present-tense reporting • She smokes. • *Look! That woman smokes a cigar. • However, via internal composition they are not states but iterated events (like pacing, bouncing a ball, etc.). • No predication is born habitual, so in the absence of a dedicated habitual marker, habitual meaning must come from an implicit type shift. • But what grammatical form performs this type shift? ECG Theme Session ICLC03 University of La Rioja July 24, 2003

7. Coercion by Tense: Present • The present tense is a state selector (Langacker 1987): • *She is ill for three days. • *She dribbles the basketball. • Present distorts Aktionsart projected by predicators: • Futures from perfective stem+present inflection, e.g., Latin amabo ‘I will love’ (<amav + o) • Habitual-event reports: • She visits her mother. (possible iff assigned a habitual reading) • ‘Progressive’ reports in, e.g., French: • Eh bien, à present, je me sens mieux. Le morale revient. ‘Now I feel better. My morale is coming back.’ (Binet, Bidochon 8: 42) • ‘Perfect’ reports in, e.g., French: • Ca fait dix minutes qu’elle nous parle de la moquette! ‘She’s been telling us about the carpet for 10 minutes.’ (Binet, Bidochon 10:17) ECG Theme Session ICLC03 University of La Rioja July 24, 2003

8. Simulation Semantics • Inspired by biological control theory, Simulation Semantics models events as executing-, or x-schemas. • An x-schema is a Petri net: a weighted graph consisting of places (circles) and transitions (rectangles) connected by directed input and output arcs. • A state is defined by the placement of a token (a black dot or number) in a particular place. • The real-time execution semantics of Petri nets models the production and consumption of resources: • A transition is enabled when its input places are marked such that it can fire by movement of tokens from input to output. • Arcs include resource, enable and inhibitory arcs. • Actions have hierarchical structure, permitting embeddings. ECG Theme Session ICLC03 University of La Rioja July 24, 2003

9. Basic X-Schema Distinctions ECG Theme Session ICLC03 University of La Rioja July 24, 2003

10. X-Schemas and Aktionsart ECG Theme Session ICLC03 University of La Rioja July 24, 2003

11. A Schema Controller iterate Ready Start Process Finish Done interrupt resume Cancel Suspend • The controller sends signals to the embedded schema. • It transitions based on signals from the embedded schema. • It captures higher level coordination of actions. ECG Theme Session ICLC03 University of La Rioja July 24, 2003

12. Phasal Aspects Map to Controller Iterative (repeat) Inceptive (start, begin) Iterate Ready Start Process Finish Done interrupt resume Cancel Suspend Resumptive(resume) Completive (finish, end) ECG Theme Session ICLC03 University of La Rioja July 24, 2003

13. Hold Find hold Stabilize Pull(self) Phases of Climb Iterate Ready Start Process Finish Done resume interrupt Suspend Cancel BINDINGS Energy Ready Standing On top ECG Theme Session ICLC03 University of La Rioja July 24, 2003

14. Hold Find hold Stabilize Pull(self) About to Climb (Prospective) Iterate Ready Start Process Finish Done resume interrupt Suspend Cancel BINDINGS Energy Ready Standing On top ECG Theme Session ICLC03 University of La Rioja July 24, 2003

15. Hold Find hold Stabilize Pull(self) Be- Climbing (Progressive) Iterate Ready Start Process Finish Done resume interrupt Suspend Cancel BINDINGS Energy Ready Standing On top ECG Theme Session ICLC03 University of La Rioja July 24, 2003

16. Iterate Ready Start Process Finish Done resume interrupt Suspend Cancel BINDINGS Hold Find hold Stabilize Pull(self) Have- Climbed (Perfect) Energy Ready Standing On top ECG Theme Session ICLC03 University of La Rioja July 24, 2003

17. Tense and Reference Time • Tense is defined by the location of reference time relative to speech time in the traditional (Reichenbach-based) view: • Past tense = E,R < S • Present tense = E,R,S • In Simulation Semantics, R is a state of the controller schema. • The location of R relative to S is captured by a time-depth representation called a sampling set: • Present = single state • Past = two states (onset and offset) • The final or unique state is the state of knowledge at S. ECG Theme Session ICLC03 University of La Rioja July 24, 2003

18. Aspect and Reference Time • In Simulation Semantics, ‘direction of inclusion’ is represented by the presence or absence of a transition between pre- and post-states in the sampling set. • In the case of the present tense, there is only one state in the sampling set. • Only states can be verified on the basis of a single temporal sample. • Therefore, present-tense reports are state reports. ECG Theme Session ICLC03 University of La Rioja July 24, 2003

19. Aspect and Reference Time • The sampling set for the past tense may include a transition between the two states. • The presence or absence of this transition captures the difference between perfective and imperfective past: • Perfective: Pat was in Cleveland yesterday for the trade show. (yesterday includes offset transition) • Imperfective: Pat was in Cleveland yesterday, and in fact has been there all month. (yesterday does not include an offset transition) • The perfective and imperfective schemas are not alternate event types, nor are they alternate construals of a single situation; they are sets of sets of places within the controller schema. ECG Theme Session ICLC03 University of La Rioja July 24, 2003

20. Aspectually Sensitive Past Tenses Perfective Imperfective ECG Theme Session ICLC03 University of La Rioja July 24, 2003

21. Aspectually Sensitive Past Tenses Perfective Imperfective ECG Theme Session ICLC03 University of La Rioja July 24, 2003

22. Type-Shifting Revisited • In Simulation Semantics, a stative type shift is selection of a state of the controller. • The combination of controller and base x-schema can (a) augment, (b) embed or (c) select a part of the base x-schema: • Augmentation: State  inchoative state, e.g., Suddenly, I knew the answer. • Embedding: Event  iterated event  habitual state, e.g., She runs. • Selection: Inchoative  state, e.g., Your soup is cooled. • Additional examples: present-tense coercion, progressive type-shifting, continuative perfect type-shifting. ECG Theme Session ICLC03 University of La Rioja July 24, 2003

23. Habituality • Habitual situations, e.g., Jan ran, count as events, just like iterated actions, e.g., Jan paced back and forth. • Habituals are therefore not intrinsically stative; they are events embedded in an iterate schema: iterate ECG Theme Session ICLC03 University of La Rioja July 24, 2003

24. Stative Coercion • Habituals become stative solely by virtue of being embedded in the stative process schema. • This schema can be selected by the present tense. present ongoing ECG Theme Session ICLC03 University of La Rioja July 24, 2003

25. Conclusion • In Simulation Semantics, tense and aspect are represented in a uniform manner. • Rather than Aktionsart plus a time line and perspective, we have combination of simulations. • Combinations model iteration, the selection of subparts and augmentation of schemas. • Using these mechanisms, we account for tense-based coercions, e.g., stative coercion via present tense. • How do we build ECG representations for tense inflections that abstract over the various morphological instantiations of tense (affixation, suppletion, etc.)? • Can we assume that English, like Romance, has both state- and event-selecting past tenses? ECG Theme Session ICLC03 University of La Rioja July 24, 2003