In linguistics, boundedness is an aspectual feature that describes a situation as having a definite beginning or end, or both, not as continuing indefinitely. Thus the clause "I ate fish" describes a unitary, bounded action, as it implies both the beginning ("I started eating fish") and the end ("I finished eating fish"). The clause "I was eating" does not express a bounded action, because the verb form does not express either the beginning or the end.
Similarly, "I set off for home" and "I arrived home" present the action as bounded, whereas "I was going home" and "I was at home" do not.
Certain grammatical aspects express boundedness.
Boundedness is characteristic of perfective aspects such as the Ancient Greek aorist and the Spanish preterite. The simple past of English commonly expresses a bounded event ("I found out"), but sometimes expresses, for example, a stative ("I knew").
The perfective aspect often includes a contextual variation similar to an inchoative aspect or verb, and expresses the beginning of a state.