Final answer:
At transform fault plate boundaries, tectonic plates slide past one another horizontally. Earthquakes are common at these boundaries.
Step-by-step explanation:
At transform fault plate boundaries, tectonic plates slide past one another horizontally. Transform boundaries are characterized by plates moving in opposite but parallel directions, resulting in shear stress and horizontal movement. These boundaries are commonly associated with earthquakes due to the friction between the plates as they slide past each other.