* Molecules in liquids are *always* in motion. Even in a liquid that appears perfectly still, the molecules are constantly vibrating, rotating, and translating (moving from one place to another).

* The motion is *random*. Molecules don't move in a coordinated way like a marching band. Their movements are chaotic and constantly changing.

* The *average* motion is what we perceive as stillness. While individual molecules are zipping around, the overall distribution of molecules in a liquid can appear static.

So, do molecules move in motionless liquids? Technically yes, but their motion is so random and on such a small scale that it's not observable with the naked eye.

Think of it like this: if you look at a busy city street, you see individual cars moving randomly. But from a distance, the overall flow of traffic seems like a steady, continuous stream. It's the same with molecules in a liquid.