1995 Chevy Corsica knocking sound

Hello - When was the last time you replaced the shocks? They could be allowing the body to bump on the springs. The upper insulator on the springs could be worn allowing body to spring vibrations. Your shocks may be loose..........with the weight on the wheels apply the proper torque to the nuts. I would also check the bushings in the control arms etc. I have attached a pic for you...........