Very very short answer question.
What does the cerebellum of the brain control?
Cerebellum: It is the second-largest part of the brain and consists of two lateral hemispheres and a central vermis. It is composed of white matter with a thin layer of grey matter, the cortex. The white matter intermixes with the grey matter and shows a tree-like pattern called arborvitae. The surface of the cerebellum shows convolutions (gyri and sulci) a number of nuclei lie deep within each lateral or cerebellar hemisphere. Over 30 million neurons lie in the cortex. Three pairs of myelinated nerve bundles called cerebullar penduncles to connect the cerebellum to the other parts of the CNS.
Functions: It is an important centre that maintains the equilibrium of body, posture, balancing orientation, moderation of voluntary movements, maintenance of muscle tone. It is a regulatory center for neuromuscular activities and controls rapid activities like walking, running, speaking, etc. All activities of the cerebellum are involuntary (though may involve learning in early stages).