# Activities Activities are a key concept behind FirstStage: they describe the time-like behaviour of things. Activities act upon a *subject* thing and occasionally other things (e.g., the activity for a character holding a prop has the character as *subject* and the prop as *object*). An activity has a Start Time and a Duration that determine when the activity plays. It is typically represented as a block on the timeline. You can drag an activity along the timeline to change when it happens. For some activities, you can also stretch the duration or trim/reveal clips: point at the activity to reveal triangular handles at the end and then drag the handle.
If you point at an activity on the Timeline and press the **Inspect** button, a menu will pop up with options depending on the type of activity.
DeleteDelete the activity from the timeline.
DuplicateDuplicate the activity and place the copy immediately afterwards. This is useful for building a sequence of repeated actions.
Split

Split the activity into two parts before and after the current time.

This is only available for clip activities which span the current time.

EditShows a screen where you can change the behaviour of the activity.
Return here by pressing the top-left arrow or the thumbpad back arrow.
This is only available for some activities like Rigid Animations.
### Keyframes Some activities contain a series of keyframes that are interpolated between. Such an activity is shown with a transparent background and a solid pip for each keyframe. You can drag the keyframe pip along the timeline to change its timing. To change the value of a keyframe you should scrub to the keyframe and then change the original property in the same way you first created it. You can also delete a keyframe by summoning the menu with the **Inspect** button. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.moviestorm.co.uk/firststage/basics/working-with-time/activities.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.