This paper studies the kinematic singularities problem faced by a 6-DOF manipulator controlled manually by using teaching pendant in real time. Two algorithms of singularities avoidance are discussed, which include non-redundancy and redundancy. Experimental case studies are developed to investigate manipulator performance when end-effector trajectories come near to shoulder and wrist singularities that are controlled manually by user. Proposed algorithms are verified to be effective and practical through experiment.