Step-by-step explanation:
When a swing is at its maximum height, the potential energy, associated with the height, is maximum. At this point its speed is zero, so the kinetic energy is zero. As the swing descends, having less height, the potential energy decreases and the kinetic energy increases. When it passes through the position with the minimum height, the potential energy is minimal and the kinetic energy is maximum.
This is true in the ideal case, in which there is no friction due to air resistance. When friction is taken into account, implies that the swing stops gradually, since its energy is converted into thermal energy