Self-broadening and shifting of methyl fluoride (CH3F)-C-12 have been investigated in the 50-408 GHz range for the rotational transitions J=0-->1, J=1-->2, J=2-->3, J=5-->6, and J=7-->8 and for their Delta M-0 and Delta M=+/-1 Stark components, as they were resolved by an appropriate field. The different results obtained for M-degenerated and M-resolved cases, as well as the M dependence of the results has been interpreted theoretically within semiclassical perturbative approximations. Evidence of collisional coupling effects between Stark components was obtained.