The cerebellum is critical for the neural control of movement, from relatively simple forms of learning to complex feats of coordination. Its highly stereotyped cellular architecture has led to the suggestion that the cerebellar circuit could perform a single computation that acts on distinct inputs to support a wide variety of behaviors. Circuit-level studies of cerebellar function have thus often focused on relatively simple forms of learning, such as delay eyeblink conditioning. However, recent work has demonstrated that even these behaviors are not as simple as once thought, and the circuit mechanisms supporting complex coordinated movement are still poorly understood. In this talk I will describe our efforts to understand how the cerebellar circuit contributes to coordinated movement, and how those mechanisms relate to the ones that support simple forms of learning.