MISCHIEVOUS is pronounced MIS CHIV ISS, not MIS CHEEVE E US.
GRIEVOUS is often misspelled and pronounced GREEVE E US. It’s GREEVE ISS.
Incidentally, looking at the subject line of this post reminds me that some people say and write PRONOUNCIATION and MISPRONOUNCIATION. True, the verb is PRONOUNCE, but for the noun forms, the O before the U is dropped.
Remember, I just teach the rules. I think they’re as crazy as you do.