Answer:
An object can only accelerate if its speed or velocity is changing. If an object's speed is constant, then its velocity may still be changing if its direction of motion is changing. For example, if a car is driving in a circular path at a constant speed, its velocity will be constantly changing direction as it follows the curvature of the road. In this case, the car would be accelerating, even though its speed is constant. Similarly, if an object's velocity is constant (meaning that both its speed and direction of motion are not changing), then it cannot be accelerating.
I hope this helps to clarify the distinction between speed and velocity, and how they relate to acceleration. Let me know if you have any further questions!