No sir, it does not. The cerebellum's function is muscle coordination, balance, etc. It operates at a unconscious level, and does not participate in cognitive functions such as thinking or speaking. The main areas associated with speaking are the Broca's area (frontal lobe) and Wernicke's area (Temporal lobe).. both of which are in the cortex. Sorry dude but it's got nothing to do with your stuttering.