The notion of event structures (Aktionsart) refers to general aspects of the meaning of different classes of predicates. It describes not the meaning of verbs, but the meaning of larger constituents that also include the subject and the objects. The four types of events typically distinguished are states, activities, achievements, and accomplishments. The main characteristics which determine the classification of events are bounding (bounded/telic vs. unbounded/atelic), duration (durative vs. non-durative), and change (homogeneous vs. heterogeneous).
Thus, states are unbounded and durative situations, and they are homogeneous since they are unchanging from moment to moment (e.g. be, believe, know). Activities (processes) share with states the property of being unbounded and durative, but they are heterogeneous, i.e. they contain an internal change, and they involve volitional agents (e.g. play, smile, walk). Achievements and accomplishments are also heterogeneous, but in contrast to activities they are bounded, i.e. they have a shape which gives them a natural finishing point beyond which the same event cannot continue. While achievements are non-durative and thus idealized to a point in time (e.g. realize, reach, break), accomplishments are, like states and activities, durative (e.g. eat, build, paint).
|STATE||-||+||-||John knew the answer.|
|ACTIVITY||-||+||+||Bill pushed the cart.|
|ACHIEVEMENT||+||-||+||The flower wilted.|
|ACCOMPLISHMENT||+||+||+||Harry cleaned the house.|
Exercises on event structures
- The flower wilted: An achievement
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