How do you speed up clips in iMovie without them staggering and only showing stills of what happens?

To speed up clips in iMovie without them staggering, use the "Speed" tool located in the toolbar or by selecting the clip and clicking on the speed icon in the inspector. Choose "Fast" and select a speed multiplier (2x, 4x, etc.) that suits your needs. For smoother playback, ensure you're not speeding up the clip excessively; otherwise, it may result in choppy footage. Additionally, consider using a higher frame rate for your clips when shooting, as this can help maintain quality when speeding up.