Sensorimotor adaptation, crucial for refining movements in response to unexpected errors, fundamentally depends on the cerebellum. The olivary climbing fiber (CF) input to cerebellar Purkinje cells (PC) acts as a “teacher” signal during motor learning and drives cerebellar plasticity. Although the CF input reliably evokes PC dendritic spikes, it is not the only signal that modulates this post-synaptic response. To disentangle the modulation of the pre-synaptic CF burst from that of its post-synaptic PC dendritic response, we simultaneously imaged PC dendrites and CF terminals with 2-photon microscopy in lobules V/VI/Simplex of the mouse cerebellum during spontaneous activity, movement or sensory evoked responses and sensory, reward and sensorimotor prediction errors. Mice performed either an active motor adaptation or passive association task. In the active task, mice were trained to push or pull a robotic manipulandum and adapt their forelimb movements to unexpected assistive or resistive force perturbations. In the associative task, the forelimb was passively displaced by the manipulandum in response to an auditory go cue, followed by a reward. Prediction errors were introduced by intermittently omitting either the cue, limb movement, or reward. Our preliminary results reveal fundamental differences in how CF and PC dendritic activity are modulated spontaneously and in response to different forms of sensory, motor or reward related signals and prediction errors. These results allow us to infer the functional significance of plasticity mechanisms that occur in the CF-PC synapse itself.